There's a lot of this answered in blogs and other forum posts, so you may want to checkt here, but to answer your question:
a) No. Our talents do not rely on crits anymore. We don't get mana back per crit, and Euphoria no longer relies on crit.
b) That's kind of vague, are you talking about PvP or PvE?
c) Right now, Starsurge, Moonfire, and Insect Swarm are the best DPS increases.
d) Haste.
I discuss the rotation/glyphs here:
http://www.owlkin.org/cataclysm/4-0-...tation-glyphs/
Please try to read through the previous forum posts before starting a redundant thread, because all of this is pretty much talked about in the first few pages of the forums, thanks.