"what kind of sanctions could be assigned by Canada against Rusoro"

Well, that gets a bit more complicated (of course). It doesn't affect the arbitration, but MAY also give rise to a separate tortious interference claim against Rusoro under Canadian law.

The elments of proof for the TI case are a little tougher than the arbitration, and GRZ may have a better claim for this related to the earlier botched attempt at a takeover. It short you have to prove that the other guy intentionally interfered in a business relationship (the VN contract/concession) causing VN to end the existing relationship, and that you sustained damages, which is the easiest element to establish here I would think.

No sanctions, money damages would be awarded if successful.

"I take it for granted that there are still enough smart lawyers in Vz. to avoid making fatal legal errors"

I seriously doubt that, I would expect Venezuela to use expensive American and Canadian firms that have expertise in international arbitration.