as far a getting alacrity from talents, i would skip those at this point. the +% looks to be multiplicative and not additive. for example, i have 8.1 force regen and with 4 stacks of Focal Lightning i have 8.4 force regen. woooo.
if memory serves, it has been known to fail a lot, force regen was bumping up to 11ish per second with Focal Lightning stacks applied.
as far as cast times go, i can't really say. all the abilities i use are instant anyways except Force Lightning of course.