Peace & Grooviness.
I can partially answer your questions. I'm not sure about the second one cause I've never listened to Hendrix or SRV other than a quick glance of em on the tv once in awhile.
Question 1) The best way to improve on anything on the guitar is practice your butt off the way you feel most comfortable. When you've been playing awhile you get to recognize how you learn stuff the best for your own way of doing things.. Like, I'll usually sit down and work on a new scale or whatever by going over it slowly as much as possible then leaving it stewing in my brain for an hour or so then going back at it again, gradually speeding it up. I just keep following that routing... pick it up, play till I can't handle it anymore, go sit down and do something else, come back to it and try again. The first few times you wonder how the heck you're ever going to play it, then after about 10 tries it starts to kick in. After a couple of days you feel comfortable and after a week it's like second nature and you don't even have to concentrate on it anymore. Find whatever technique works for you and just keep at it. Find some scale excercises that force you to use all your fingers.
Question 3) A 12 string is almost identical to a 6 string ie, it's played the same way, cept each string is doubled up (3rd to 6th strings are double up an octave apart, 1 and 2 are just 2 of the same string) The main reason for a 12 string is the unique sound. For an example of fingerpicking one Supertramp -Even in the Quietest Moments is the only one I can think of off the top of my head... I think the Beatles Hard Days Night uses one in the lead too.

[This message has been edited by schmange (edited 07-07-2000).]