Sorry, haven't visited your thread for awhile.
Sure, supporting the wall or roof with bottle jacks is a good thing. I made a "T" as a jacking support with 2x4's. I put a piece of plywood or cast off engineered wood under the jack to spread the load. The jack came in real handy to repair rotted ceiling joists.
Your picture brings back memories. :)
One tip I can share is to write out a building plan. It doesn't have to be a CAD affair or even correct scale. The purpose is to have some idea about what goes where and when it needs to come in the schedule of building. I surprised myself by only leaving out a couple of things, the dedicated receptacle for a 120V fridge and the audio feed to/from the television location to the entertainment equipment. I was able to get those in before I had wall paneling up so recovery wasn't difficult. After I had the paneling up and was installing light switches, I thought I had forgotten the switch box for the over-sink light but I had just forgotten to cut the paneling. A pass with the router and the box was exposed.
Keep us posted on further developments.