WotLK Unholy PvE Questions

[Eythex]

Haste vs crit, Just wondering what is better, and if i should gem for any of them through yellow sockets, or just go all str gems and make do with whatever crit and haste i get with gear?

Also, which is better for low-mid gear range (5k gs atm) frost sub spec or blood?

In icy veins i saw a spec for duel wielding uh without scourge strike at all, that'll enable using two runes, which could buff the magical damage portion of uh. Is that relevant?

Are there any spreadsheets I could use to get some answers by myself?