Not sure if you guys happened to hear me saying it before, but I too dislike the chain system.
Moving on...
Dodge -> I would like to see it too. Sounds easy enough to implement
Ready -> That, on other hand, should be complicate; and from a player perspective the result does not worth the time consumption. AMOF you even need to "confirm" the activation of your prepared action using your reaction when the trigger happen.
It's basically the XCOM "overwatch". Except it can be both a melee and a ranged thing in this case.
Height advantage/disadvantage -> It's not 5e but I like it! It gives more "meaning" to verticality and to position on the battle field, and mainly because it does make sense.
it gives, in fact, TOO MUCH meaning to verticality, factually making so that just being a couple of meters above the target is more than enough to trump/make redundant countless spells and class-specific abilities.
Make Wizard not been able to cast all spells -> By the Nine Hells, I really agree with this one!
I still consider this a bug/non-implemented feature. I refuse to even consider the idea that they could actually evaluate this a proper feature.
Chain L. C. -> I agree that it is a system that should be polished, but it's a minor thing IMO.
No, it's not. It's a terrible UI/control scheme, that can single-handedly harm the enjoyment of the game.
Even my very recent discovery that Larian at some point DID implement a keybinding for "chain/unchain all" (it's called "TOGGLE GROUP CONTROL" and unbound by default for some UNHOLY reason) can only mitigate the frustration that this system causes only to a limited degree.
Because at its core it's still bad and the only way to salvage it is basically to not make it work as it does now.
Also, I'll joing the "Team Calling Bullshit" when it comes to the argument "Reactions slow the combat". How does it "slow the combat to have more chances to intervene/actively participate to it rather than just being a witness while you watch 15 NPC queueing their actions after your turn?