I tried making something challenging but approachable, but I guess Braixen is a little broken to this point on the game.
At the same time, the powering thought using only your over-leveled starter is something we all have done at least one.
About the leader team strength/level the problem is that if I were to build her team using only Braixen level mons, nothing else you can get at this point of the game would be able to do anything more than taking one or two hits while you heal Braixen; and I didn't wanted to set a level cap since that would make seeing the Braixen scene after fighting the gym a grind fest.
But the idea is that as you progress through the game, as the regular mons evolve and learn new moves the gap between them and the lewd mons will be reduced, and I'll get more room to build more busted up teams for the other trainers.
And I'll look into those bugs, for what you say they don't seem to be game breaking so I'll probably save them for the next big update.