there are two websites that host time trial leaderboards:
https://www.mkleaderboards.com
both of them should be able to verify your times with no issues :)
Of course you can use both the keyboard and mouse and the same time! Steering Bounce without the keyboard is a pain, it's way better to use it
beating the game while not rolling is totally possible, I've even done it a couple times. In that case No Rolling would probably make the most sense. I'll talk it out with the other mods and maybe we can add it as a CE
So long as you finish all the races you should be good :)
literally tried it out for an hour on stream and only got it 5 times :)
If it ain't broke don't fix it...?
https://www.speedrun.com/redball4v1 this is one thing https://www.speedrun.com/redball4 this is another
fin.