Can you guys weigh in on RAs?

I think it matters a lot what aspect of the game you are building for. Purge isn't really all that if you just PvE for example.
Keep in mind too that your goal as a reaver is usually to get as many Leviathans in during a slam as possible - you do more damage based on your style procs then physical damage, so fast weapons are key.

Good for PvE:
MoParry / MoBlock
MoArms (unless you can use a fast enough weapon and haste to hit the swing cap without it)
Serenity?

Good for all RvR:
Purge
LW2

Good for Solo:
FA -> IP
MoParry / MoBlock
Unquenchable Thirst of Souls (I would test this now and see what kind of damage it does to see if it's worth while).
See MoArms comment

Good for 8v8:
See MoArms comment
Avoidance of Magic - A poor hybrid's Determination, I would consider running a lot of this if I wanted to 8v8 on a Reaver.

Also note that with Wild Arcana you can crit your debuffs which can be pretty awesome Maybe something to think about later.

Any way to crit the Levi proc? At first glance it seems the answer is no

No. Im personally going lw2 (a must for all albs i think)..aug dex 2, master block 1/2 (havent decided yet) then purge, then probably fa2 --> ip..

Granted im only pveing to template..will solo and small man almost exclusively

Could in theory not go dex/moblock at all and rush active RAs but im of the opinion you get more use out of them..especially in 1vx situations