Personally, I wouldn't go all out on Thought Control alone.
8 Will is enough for Neural Overload to do what it's meant to. The rest of the TC skills will take some time, but they will get there for the big fights. You'd have to focus on some other things in your build to make sure you get the staff early on, though. Considering it's also a spear that applies poisons, intimidates and blocks, you could make use of that, as well, no? It will be interesting going all out on with that weapon. For some fights you could make use of a Tac Vest with Psi Crab Carapace. Not always, mind you.