I agree with pretty much all you said. Jump is crazy, and I don't know about anyone else but I think the shove thing is just as bad. I don't know 5e well but isnt there a 5 step rule and shove just kind of replaces that in this game? I just think shove and jump trivialize a lot of the combat.
None of these things are 5e.
* Jump is a supernatural feature caused by the tadpole, but Disengage is an Action in the rules instead of a Bonus Action. Some classes have special Disengages as Bonus Action, namely Rogue and Monk.
* Shove is also an Action. I think it should also be in BG3 because it can be OP ! It is fun, but changes the combat significantly when done right. Using an Action (instead of a Bonus Action) to shove someone down a pit would be worth it.
* In 5e, the 5 foot step does not exist. But you can move anytime before or after your attacks. The 5 foot step is not really necessary in 5e as you provoke an AOO only when you leave the reach of the enemy (i.e. unlike former editions where moving around adjacent could also provoke an AOO). That point is well implemented in BG3.