Hello!
First, I am predominantly using keyboard; I haven't tried a controller yet, though I am presuming the game detects a controller
The backwards bike thing is a great description! Yeah, we generally recommend new players play with a controller since that seems to hook more directly into their brain (up on the stick means up, down means down, there's two sides, got it). This is definitely a hump to get over for getting into TS. Interesting point on the extra buttons -- something we'll definitely think about.
Second, I found an aura that told me to spend it (to get random items). No idea how to do that.
Yeah, that one is unfortunately broken right now I think :(
Thirdly, there are a some offensive seed types that sound like they have ways to control them, but no idea how to control them based on the text like "planted pads"
Most seed types you can't control, but if you can they aim away from the seed's position. We're definitely thinking about good ways to describe this aspect of certain seeds, since it's not something covered in any descriptions right now.
Apologies for the slow reply -- we've all been a little scattered with the holidays. Happy new year, and let us know if you have any other questions!