I mean, aside from the fact that the numbers are all rather low, they seem appropriately apportioned yeah. Depending on where you plan on using him the speed may be on the low side - if your goal is to have him be an arena freezer, you'll need him much faster.

I'd sacrifice attack for speed even if he's not going in the arena. More speed equals more opportunity to build up that passive. If you get it capped, that's a 100% attack bonus and 25% crit damage, which will be made all the more effective by having the speed to attack and place those debuffs more often. Unless the fights are too short to build it up, I suspect it'd be worth it.