O scale layout advice

#1) You can place the track wherever you want but you can’t go so close to the walls that the trains will hit the wall. I would be more concerned about any trains taking a 7’ drop to the floor. I would put up some kind of a guard rail or a piece of wood at least an inch high in case of derailment. That’s just what I would do. Murphy’s law you know.

#2) I would use a modern transformer for modern locomotives with electronics. Your transformer from the ‘70s is great for PW trains or trains from that era but not for modern trains with electronics.

The railing is a good idea. I didn't think the old transformer would work. Thanks for taking the time to advise.

If you do a search of "ceiling layouts" here on the Forum, you should get quite a few threads that you can scroll through to get ideas and look at potential issues.