hey jason...i'll answer your questions in order...or try to....
first off when you say "you feel the yoyo hits your finger in different places" what do you mean? the yoyo shouldn't hit your finger at all....or do you mean string? if string is the case, then yes, it should be hitting your finger in different places...take double or nothing for instance.
The most important part though, is that the last two points that connect are perfectly straight and aligned with the yoyo.
(this would mean the string segment furthest from you) it doesn't matter (to an extent) how "angled" or whatever the strings are that aren't touching the yoyo, just as long as that last segment is straight.
you can touch your elbows to your sides, but it wont' help much because you'll need control from your arms in order to keep the yoyo straight I think......
i usually keep the yoyo hmm.....wherever it's comfortable. for different tricks, it's different, but I guess it's safe to say that my upper arm is usually facing down and only my forearm is extended.
joints? hmm...i dont' really AIM for joints...unless i'm doing something like black hops hahah (still can't finish it completely).
i HOPE this helps...and i probably didn't make any sense
