Oh hey! Didn't expect to see you here! I'm Skai!
1) That's a good question... It sounds a little tricky to implement given the state of the code, but I can take a look.
2) Unlocking shuffle as an upgrade is a good idea. It's planned to be free use, so that would balance it. As far as stage time, the earliest versions of the demo had timer increases, but I don't want to go that route because I'm trying to shy away from any upgrades that make the game go on longer.
3) I'm aware. She's gotten a rework where she gets a lil plumper. ;D