Noob Guitar Hero 2 Q's (X360)

[Daliman]

I just got this game 3 days ago, and I love it( I never had any previous incarnations on GT). While I am happy with my progress, I am not even in the realm of many of you. It appears most don't even bother playing the easy level, but I'm going ahead and baby-stepping through it, and will not move to the next level until I have solid 5* performances on all songs at each level. I have 5* or better most of the songs through the first 5 levels, although 4 and 5 I haven't played more than once or twice each, and am annoyed to find my OCD often prevents me from getting 100%s and close, as if I'm on a note streak, all the sudden my finger itches, or my neck tickles, something stupid. OCD is annoying...

Anyways, on to the Q's (some literal, some opinion)

1. How do you to get to play encores?
2. Does using the whammy bar add points(pretty sure this is no, just Star power energy on starred long notes, but not positive. Does it add points on Star power notes?)
3. Are guitar players inherently at an advantage in this game, and conversely, would learning to play this game at a high level likely make it easier for you to learn to play guitar? I would guess both are true, as I envision all these guys that are crushing the game play guitar already, ( obviously I know even a fantastic guitar player would have to assimilate himself to the game before being awesome.)
4. I personally always strum up; is there any inherent advantage to strumming either direction (or both)? Or is it strictly a comfort issue?
5. When I first started, I would always press the fret in exact time as the strum like a control button, even if it were 5 or 6 notes in a row, letting off the fret to press in time each time. I assume this was poor form, am I correct?

All I can think of right now, TY for your patience with a GT2 noob.