Is there a way to lock a scene once I get it just ridge with actors and lights and camera? Often just before I can render something shifts minutely or broadly, but it spoils the shot!?

drawn

You can lock things, but it may be a bit tedious. Under the object menu, there is a lock object option. The problem is that you must lock every body part for every figure and every prop individually. There is no option to lock them all at once.

You are likely moving the items as you select them. It's easy to do if you're not careful, especially if you don't have a steady mouse hand. If that's the case, I recommend using the hierarchy menu to select your items.