If Intellect is 3.1 and crit is 1.62, then no.
(80*3.1)+(1.62*160) = 248 + 211.2 = 459.2
1.62*320 = 518.4
As has been mentioned many times, stat weights vary according to gear. If, at any point, crit is worth more than half of Intellect, it's beneficial to gem pure crit.
At 12049 Intellect (my gear), I gain 5.67% crit. This means that 1 intellect is worth a TINY (0.0004%) amount of crit. 80 Intellect grants us 0.032% crit, equivalent to 19.2 crit rating, thus should almost be ignored when coming to calculations.
Depends on what you mean by 'raw' DPS. All 3 specs are performing well in comparison to others, with Fire coming out on top of the Mage specs. Sims suggest Fire being 2nd best overall DPS spec (behind Aff Locks) in T14 HC gear.