Review of original post and my list of suggestions to include:

0.2) include difficulties (single most powerful feature to please them all):
story +8, easy +4, normal +2, hard +0 (untested values) unconditionally to all d20 rolls or spell DCs for player characters; this will make it very hard to casual players to miss, e.g. AC15 creature in story mode would not be hit only on Nat 1 (95% hit chance without advantage; 99.75% with), in easy mode on 1-5 (75% w/o adv.; 93.75% with)
Using these values globally has an effect on attacks, which Larian already tried to change, but also save based spells (most of spells) and dialogs
# the above expands on your first point in 0.2 quite a bit with some numbers that on the surface look like might work well for both casual players (story / easy) and D&D fans (hard)
1.2)
# Shove ideally would be an attack and not a (bonus) action; 5th level Fighter, Barbarian, Paladin, Monk & Ranger get extra attacks, so they should be able to shove two creatures or try to shove one creature twice
# Noticed a bug: “You make a strength (Athletics) or dexterity (Acrobatics)” can only use strength (Athletics) and I think it’s how Larian implements it. Can use dexterity only when defending (i.e. you use force to shove, but you can either use force to cancel the effect or try to avoid it with dex). I would also include “The target must be no more than one size larger than you” to shoving, because it’s hard for me to imagine 30lb Halfling to be able to push 600lb Ogre.
# Help as bonus action or reaction falls into the same problems as described by Isaac in 0.1) (free Advantage that kills many skills and abilities that cost full action and/or resources). For 3 minutes explanation of cool effect of Help as an action: https://www.youtube.com/watch?v=1Vmc3ka7CsM
2.1) Climbing in D&D normally costs twice as much as walking, so if you want to climb 30ft ladder, you have to use two turns (or Dash). Stopping in the middle of the ladder if you have no more movement should be a thing (potentialy not being able to use action like attack with a bow). There are special skills that make climbing faster, e.g. lvl 3 Rogue Thief: "you gain the ability to climb faster than normal; climbing no longer costs you extra movement”.
3.3) Yes, light seems buggy.
3.4)
# Help gives advantage, so doesn’t stack with other things that give advantage
# Attacking prone target (from 5ft distance) gives advantage, so doesn’t stack… (see my 0.2) suggestion)
5.1) This looks very good: https://forums.larian.com/ubbthreads.php?ubb=showflat&Number=702825#Post702825
6.2)
# Remove monetary cost of writing spells into book (cost is a thing in D&D, but I feel it doesn’t make sense with money devaluated by access to too many magical items and being able to steal thousands easily)
# Don’t add monetary cost to spells (e.g. Familiar), unless the cost is very big that it would matter (same reason as above)

Well done on collecting feedback. Keep it coming!