@Simple_Man81
I live in zone 5, between Chicago and Milwaukee, obviously your California climate has a much, much longer growing season. So how long to leave it recover? Use your judgement, in my climate I think I would need to leave it 3 to 5 years, but you have better conditions, I would guess at least 2 years, not less. You want to give all those new buds and new roots time to form cellulose and lignin, they need to become woody to be able to resist vibration, jostling, and other accidents and unplanned movements that will happen when working on the tree. Warning, carving the tree with power tools will cause the trunk to vibrate, which will travel down to the roots. If the tree is not firmly rooted in, so by hand you can not wiggle the trunk, the roots will get broken by the vibrations of using power tools, die grinders and those ''mini chainsaw'' looking things cause the most vibration. I only do power tool carving in middle of winter while my soil is frozen rock solid. If the soil starts to thaw, I put it back outside to freeze again. You will have to wait until the tree has firmly filled the pot with roots, at least 2 or more years from now, before you use power tools.
I realize your tree was chosen because ''it was there'', and indeed you can with skilled carving, make an interesting tree. I suggest while you are waiting for this one to establish, find dead logs, about the same size as your tree and practice with your power tools, see if you can create the types of images were talking about. I have seen some decent trees ruined by their owner making their very first attempt at carving to carve their prized tree. Carving takes practice, best time to start is now.
I would also pick up Japanese Black pine seed or seedlings, in your climate you can create some decent trees from scratch in 5 to 10 years. Also, look around your area, some of the burned trees and brush, you might find some interesting trunks with cool fire damage. Some of the oaks and junipers and sagebrush could work out well.