I would love to see an improvement in the value of the weekly gachas. There was a time I was happy to spend money on this game on a regular basis.
If that's stuck being a thing of the past, then I second the more FGs or better gacha results. I've been playing this game for nearly two years now and I've only ever successfully pulled one 6*.
Oh, and I almost forgot! Please bring back the ability to buy rainbow dress blooms with FGs. I know, I'm being greedy now.