Worth starting now?

[Palm_Tree]

Hello there. Long story short, I'm thinking of giving SM (or FFR, maybe?) a go, though I have a few small questions.

1. Would you say the community is, well, there? Although I don't mind a small (but active) community, is it declining, stable, or growing? Or is it pretty hard to gauge at this point in time?

2. How does SM compare to osu!mania? I hear the judgment in o!m is pretty horrible, though I've stumbled across videos from greats like Halogen and Staiain playing o!m a fair bit. Should I be playing o!m instead if I want to play a vertical rhythm game? Or would SM be a better choice?

3. Are there any beginner packs you would particularly recommend for learning keyboard play? I just downloaded Stepping Stones of Stepmania; is that a good one to start with?

4. On OS X, running SM 5.0.7, how does one change the arrow speed? I searched through the arrow speed sticky and can't seem to find information relevant to my current state.

Thank you very much.