Re: "Extra careful"
Any time you want to get wacky and experiment just do a Save As of the project then go nuts. I do it all the time. If I destroy the project or crush the computer I can just revert back to the previous version of the project.
I'd say about 50% of my "experiments" end in flames. When that happens nothing of value is lost but much is learned (which can then be applied to my REAL projects).
As for Track PC to Bus PC.... don't see an issue but I don't know if the Compressor module will retain it's state (Track vs. Bus version). Probably will.