I'm kind of on the fence for this as well, on one hand if this is the only mod you use, adding a native mortal magic system makes sense, on the other hand, other mods exist that are dedicated to adding mortal magic systems and perhaps having a compatch or something that makes them play nice together as if they were meant to be used together also makes sense. In this way, I'd rather that if a mortal magic system was made, with this mod in mind, that it was kept as a separate submod or something like that so that you can use the magic system that you prefer, or in the case of EK2, that comes with the total conversion.

We definitely do need more blessings however. The blessing interface is a bit confusing as well on that subject:
- Beauty/Physique/etc blessings work from the bottom up, each blessing downgrades a negative trait if present or upgrades a positive trait if present. This makes sense, and requires you to bless the same person with the same blessing multiple times to fully grant them the highest blessing possible. In theory this would allow you to sort of invest in some mortal characters at varying levels and it's a good thing.
- Blessing of X blessings are a bit messier, the first time gives the full normal blessing, and the second time gives a lesser blessing which is confusingly a different organization system from the prior trait-based blessings, I believe it should go more like Lesser -> Normal -> Greater (the latter of which doesn't appear to exist), or some such, as opposed to what it is now. Also, these blessings are lacking in their quantities and effects, iirc there's one of the 6 main stat that isn't affected by any of the 6 blessings, and it's a shame cause a blessing that affects it should exist as well.

I haven't looked at all the abilities granted by the mod in detail, so far, but that above was definitely one of my biggest annoyances. The other annoyance being that you're not really given the option of creating your own religion, which I assume will come as part of the Domain system? Regardless, having your Divine character believe in Catholicism is extremely weird as Catholicism isn't polytheistic so it sort of conflicts, unless you're pretending that you're the God, but it just feels off that a religion that's so well established can be co-opted that easily by just creating your divinity to have that religion. It's just kinda off. There should be a Decision to found your religion, if possible, or convert you to a religion that you can then reform to get "your own religion". This is a bit more complicated however cause you could want to roleplay as a new divinity of many pantheons, from the norse, the greek, the egyptian, etc. So those that are missing would have to be added and such, and the option to just go your own patch and start your own religion based on no specific religion should also be an option. I am not sure how possible all of these ideas are, tbqh.

Those are good points!
For the thing with the lesser blessings, the point is mostly that the lesser blessings stack, meaning that you can do the major blessing for relatively cheap, get a big bonus for the relevant thing. After that, each blessing costs more and has a smaller effect - you could get someone to a 100 martial, it will just cost a lot.

As for religions and pantheons - I recognize the desire to have your own religion, is the -100% cost to reformation/faith creation not enough? I think creating dynamic religions in game is something very complicated engine-wise, so this is the best I could do without much effort.

I do admit my intention for this mod is less Pantheons and more each divinity having their own religion - with possibly the ability to create 'Slivers', or 'demigods', that are imbued with a large part of your divine power. Think less Norse gods, and more Daedric Princes