Thanks for the detailed feedback, glad you enjoyed it!
Shouldn't be any more slowness against gyms than anywhere else, it's possible that some bots had a Grass on Grass fight somewhere, these take a second to process
Difficulty indicators are a good idea, should probably say the exact levels instead of "Difficulty 2"
The battle against Barry in the video didn't allow you to do it because he had no team - someone has already beaten him, after that he gets a new team in 5 turns. It's mentioned in the tutorial, but wouldn't hurt to say it in the box on the bottom too. I guess a lot more could be done with that box, now that I think of it.
Thanks for playing! I'll watch the full video later