I agree with most stuff.
We definitely need the ready and dodge action.
I did not play Solasta, but shadowrun had an option to ready an attack, so you end your turn but you will do an attack as soon as an enemy comes into range of the weapon you have equiped now.
We also need spells as reaction ( shield, feather fall for example )
one thing I am not sure is your point: use bonus action as action.
I have not played PnP, but I found no rule that you can use an action to do something that is described as bonus action.
There is a rule that you can only use one spell per turn, unless one of the spells (action, bonus action, reaction) is a cantrip. This is not implemented in BG3.
Maybe someone with PnP experiance can help here.

Prof. Dr. Dr. Mad S. Tist

World leading expert of artificial stupidity.
Because there are too many people who work on artificial intelligence already