Just a few sugestions.

[flymar]

You have a perfect base game. Now not to fork it up
Probably noone will read this but TQ is one of my favorite game (I bought it 3 times already - box/Impulse/steam - and I had to write this.
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1. speed
- keep it slow
I friggin hate current aRPG where all characters move on steroids. TQ was perfect, decent speed exploration
2 ragdoll
- one of the iconic things in TQ
- other game tried that and failed. it's not easy to pull off, but seeing crock being smashed out of his armor and off the cliff is satisfying.
3. more content in game +
- I don't know the structure of the new game but I do miss game+ modes. Way to appreciate the starting levels with new shiny gear with new, harder enemies and new epic bossess
4. endgame - maybe, but game + is a must
just the above
5. shrink the game to bout 60%
Exploring in TQ was great but the areas were just too big. And backtracking in those huge maps are pain in the butt
6. if one character - make different body types/heads
If you're going to use TQ method (one character shaped by masteries) please give us the choice of body type. From thin to fat. Make it visible.
7. random maps
I don't know why we lost random maps in current games - probably because Blizz scrapped them in D3. But it was so refreshing to not knowing what's behind the corner
8. dyes - if you wanna have them - make it count - I guess the Guildwars 2 had it the best way. So dyes as loot, with common, uncommon, rare system, fabric/leather/metal/fur texture. Outfit/weapons made with few layers.

[Pedde]

Agree with most of what you are saying, but:

4. I'm really torn on the endgame. TQ's strong suit was always the long campaign and what we call New Game+ today. It worked well in TQ.
5. What areas/maps are you refering to here? I found the base game (Anniversary without newer expansions) great in that regard. I think the annoying backtracking only occurred with the new expansions, most specifically Ragnarok. This is why I disabled Ragnarok for good and went back to playing Anniversary Edition + Atlantis. Atlantis only for the features, not the campaign. So when we are talking about the base game, I don't think any maps need shrinking.

[armarant]

I also enjoyed static maps. This helps cut time on future playthroughs.

[Scipo0419]

Agree with most except map size as that's relative to game speed and random maps.

I used to feel like we needed random maps like in D2/D3 for an ARPG to feel fun and interesting, but after playing TQ and Grim Dawn. I'll 100,000% take a handcrafted detailed map with lots of love and care put into it over a handful of tiles stitched together. D4s static map failed because it's just an empty canvas for the devs to put enemies in where Titan Quest and Grim Dawn the maps told stories (especially Grim Dawn)

[flymar]

More about map size,
Usually when I start TQ game, I tell to myself. "Now I'm gonna explore everything. All of the caves and stuff. But that's the feeling for about 2 areas:) Then inevitably I'm going to rush.

And random maps, I don't mind spending more time in game+ to explore them, As for repetition.., well I feel devs are most creative in starting areas, Later it gets generic this way or another:)