I’d be happy with just #1, as well.
But i suspect that the reason they changed the system in the first place was to discourage droppers (too many low level players complaining about high level opponents in their arenas. That’s why i would be fine with #2.
#3 would be an easy addition. just some light coding and a new background.
#4 - just to add some challenge for the upper echelon, since they complain about not enough human opponents and AI are too easy.
The current system is horrible. Might as well not even have trophy counts and rankings, if there is no way to advance to a higher level. When i field my best team, i’m matched against opponents with hundreds of trophies more than me - if i win +30ish. if i lose -30ish.