I personally have a need for lots of rhythmic freedom, whatever I'm playing, which is one of the reasons I tend to gravitate towards legato when playing fast. However, sometimes that's not an ideal sound, and sometimes it simply won't work for what I want to play, and so alternate picking is necessary to get the sound I'm after. The problem I face then is achieving the same level of rhythmic freedom while retaining hand synchronisation.

A good example would be this (brilliant) lick for Satriani's Devil's Slide. Musically it's a straightforward blues scale rock lick, but rhythmically t's rather loose and uneven.

(the yellow square is simply where I was when I print-screened the Guitar Pro file)

What's the best way to practise hand synchronisation in such rhythmic situations? And how are licks like that best learned note for note? When I slow it down it seems to lose all direction, making learning it a lot harder.

(and incidentally, should I just straight alternate pick a lick that crosses strings like that?)