1. In PathFinder, there's a small little box that you can drag files to and it will hold them and then you can navigate else where on your file system and pull the files from that box and put them where you want them.
2. Nope, I have this turned off and they still go to sleep and they take 5-10 sec to spin up whenever I go into any Finder window with an external drive connected. Really obnoxious...
3. Yea, I think it should be optional.. similar to how Safari works if you don't initiate tabs. There there, but you don't really notice them.