I'm not convinced that this stuff lacks balance. It seems to play out well in my games.
That is great that it hasn't been a problem for you, but everyone else clearly has a problem with it. Also the change seems to have no purpose other than to frustrate the player. I literally stopped playing for a while after a frustrating combat where my gith fighter spent the entire combat frightened.
The "everyone else" argument is simply nonsensical. You assume everyone thinks alike.
Additional effects add complexity to the game, which is always good and they are definitely not even have half of power of current battlemaster maneuvers.
As for the fear effect I like it, it is quite satisfying to see your character turn the tide and let you win lost matches.
Stronger effects are also the only way for martial classes to keep up with the mages in any way.
There will never be a restrictive rest system in the game which makes magic classes much more powerful than they should be.
Unfortunately, there is no chance for this to change in the full version, it is extremely difficult to do correctly and even then it will not be liked by most players.