This post contains a number of FAQ's. Please read these before asking questions in the comments.

ATC is not loading!
As per ATC's installation instructions, you need to run a campaign first to add the files. I would suggest loading a sandbox campaign, then cancel back to the main menu. That should install the files.

If you need to affect the ATC settings, DRM now adjusts those as part of its own configuration file. If you want to make tweaks, I would do it there.

What ATC settings are critical for DRM?
The most important two are <EnableCustomTemplates> and <EliteOnlyInCastleVillages>, both of which must be set to False for intended DRM functionality. Otherwise, ATC will create mixed (and often leveled up) parties for lords and minor factions (the latter getting vanilla units too!), and the latter will result in elite pool units being all over the place.
I would also suggest setting <LevelRecruitsUpToTier> to either 0 or 1 to ensure that ATC does not automatically level up recruits. That said, you are welcome to increase it if you would like to create a higher harddeck for recruits, but be aware that you may not be able to select what upgrade path the unit takes!

Other settings may be tweaked to the values that suit your enjoyment of the game best.

What settings should I use in RBM?
From RBM, you are only required to enable the Combat Module and within that Shoulder Shields as DRM relies on the combat module for balance and some items. All other settings, including whether you even use the AI Module, are up to the individual player.
Yes, this includes Reload Speed as that setting only affects the player - the AI always uses Realistic reload speed.

What settings should I use with Better Pikes?
Currently I do not have recommended settings. A general rule of thumb is that you should set the pike damage multiplier to be high enough that pikemen do not draw their sidearms.

If I do not want to use Better Pikes, do I need to make any changes?
Yes, to avoid pikemen preferring their sidearms you should go through the troop XML files and remove them from all pike units except for the Vanni Beastslayer (who are intended to switch between sword and pike). I would recommend Notepad++ for this.

Q: You mentioned manuals. Where are they?
They are in the Articles section of DRM's Nexus Mods page[www.nexusmods.com].
Be aware that while this is not required reading, it is useful information that I made available to help acclimate players. If you have comments about troops, I would ask that you read the manuals regarding that unit or faction first.

Q: I have balance feedback! Where do I leave it?
Comments here or on DRM's Nexus page will be fine. Be aware that I cannot promise changes to every comment about balance, but rather I use it to guide what to look for and investigate. In this context, the more information you can provide (such as when a unit is over/under performing) the better I can recreate the situation and examine it.

Q: Is there anything I should keep in mind when reporting a bug?
First, check "Known Issues" before reporting it. It may be something that I have been unable to fix or is a TaleWorlds issues.
If that does not apply, the more information you can provide about the bug, the better. Vague bug reports are effectively useless, but ones with detail I can better identify the issue and give feedback as to what is the cause may be or if it is even a bug with DRM.
Note that I take no responsibility for any crashes or bugs that occur as a result of you modding the files to your own preferences. I may provide advice if asked, but I will not fix it in that case.

Q: How long is the turnaround time on bugfixes?
That depends entirely on the bugfix. Major game-breaking things I will look to release a hotfix for if I can find one. Minor things that are annoying but can be worked around (or could be beneficial to a player) I will usually leave to be part of a larger update, especially if I have one in the works.
Note that if I cannot recreate the bug and request more information such as a call stack from Better Exception Window and I do not hear back from you within one week, I will close the bug report.

Q: Conspiracy Quests still use vanilla units. Are there plans to mod them?
Given that this is a TaleWorlds main quest function, for now I am not going to implement a revamp of the Stop Conspiracy party rosters. Once the game is released in full, I will revisit this.
In the meantime, I would recommend only bringing your best troops to raid their hideouts and bring an army to fight large raiding parties. Most elite units should have enough armor to go toe-to-toe in melee and bring enough armor-piercing to negate their own.
Alternatively, you can just skip the main quest entirely. You won’t ever have to contend with Conspiracy units at all in that case, and frankly the Main Quest is not very well implemented anyways. And with Sandbox Mode added in Bannerlord’s 1.5.9 update, you don’t even need to fuss about it in the first place!

Q Will there be Beta build compatibility?
Ultimately I have chosen not to support any of Bannerlord's beta builds with DRM. This is primarily a matter of keeping the urgency of updating DRM down and to only have one version of the file to maintain.
The reason for this is that, especially when I'm playing Bannerlord, is that I'd need to disable all my mods, load the beta version, load the beta version of the dependent mods if necessary, make the changes, and then once I'm good set everything back... only to repeat the process if TW changes something in the beta build.
If you like playing the latest and greatest beta version, by all means go for it! DRM usually only breaks when TW changes how troops, parties, or cultures are specified in the XML files, otherwise it can usually work once the mods it depends on are updated to the beta.

Q: What is the split for Irregular/Regular/Noble troops?
Varies by faction, and is listed in the respective Faction manual article over on the Nexus. Generally, Standard troops will give you a large pool of irregulars with some lower nobles (~80/20 split) while the Elite troop pool from sufficiently powerful Notables will provide you with Regulars and the proper elite Nobles of the faction.
Note that due to casualties, attrition, and chance involved with spawning that these ratios will vary in individual parties.

Q: Why do some trees have their tiers end earlier than maximum for that type? Doesn’t that make them less effective and make the branches less attractive?
Yes and no. It does indicate less potential, but at the same time I think it is also a way to be more honest about the weaknesses of a faction or where a unit has achieved a ‘good enough’ status for its role in that faction.
Do not overlook them, however. They may not be the absolute best in their field, but they will usually be effective within their context.

Q: Are the troop trees meant to improve the realism of Bannerlord?
I would say that the goal was “Thematic Realism” - grounded in realism but with liberties taken for thematic or technical reasons. Mount & Blade has always been anachronistic, after all.

Q: Does this mean balance is left to suffer?
That probably depends on what you mean by balance, but generally speaking I have aimed to try and balance things within the theme of the mod. Elite units are powerful, but correspondingly rare and you will need to get the necessary support from notables in order to mass them. Accordingly, irregulars are cheap, easy to get, and easy to train up with the right skills but there will be a ceiling on their ability to improve.

Q: Why is there no [X] in a faction?
That would depend on what [X] is, but in general I tried to avoid cramming as many unit types as possible into a single faction to avoid unnecessary clutter. Vlandia may be an elite crossbow faction, but do they really need noble crossbowmen as an alternative to their Knights?

Q: And female troops?
No dedicated troop trees, though I would recommend the Treeless Female Troops[www.nexusmods.com] mod as it achieves the same goal without any clutter. Use whatever values you would prefer.

Q: Can I make my own units to use with this mod?
Yes, you can create your own units but you will need to add them yourself. To leave room for this I deliberately did not assign any ATC configuration for the player kingdom or clan, but all the standard factions have been set.
However, once you start modding the files I am not responsible for any crashes or other issues, so you do this at your own risk.
Furthermore, if you would like to release a submod I would ask that you do me the courtesy of reaching out to me first.

Q: Will recruits change based on who owns a settlement?
As of DRM 3.1.0, yes. Cross-factional units have been implemented, though there are a few gaps where it will default to 'more irregulars and fewer regulars for the invader'. These can range from regional auxiliaries (or using Imperial infrastructure to field such yourself as the invader), local cultures being reasserted to break down the existing hold, or even just the invader's units. See 'Cross-Factional Units' in the articles section for details.
However, you can adjust this if you wish by tweaking the ATC configuration file in your download.

I don't like RBM. Can I get a version without?
No, I am not going to provide a non-RBM version of DRM. I simply do not have the personal bandwidth to maintain two versions of DRM built on entirely different balance paradigms.

Q: Are more changes planned?
As of DRM 4.2.4, there are (smaller) reworks planned for the Empire, Vlandia, and the Aserai as well as finally updating Story Mode. I also intend to integrate Open Source Armory into DRM at some point, but due to the size of OSA I want to wait until I have finalized a vanilla version of DRM so I can leave that up for those who do not want to use OSA.