No, you don't need the t-handle bolts, but, you do need to take extra care with making sure the bolts don't get epoxied into the pillars/stock. A good release agent is your friend. Along with some clay to fill holes/cavities in the action. I do the pillars and bedding separate. Doesn't matter to me which is first. Just easier for me to 'manage' one thing at a time. The last one I did was pillars first. The one before that was bedding first.

FWIW, usually the pillars end up seated against the action. That's how my BVSS came from Savage as well.