Making gamemode, few questions

[fantastic]

I'm curious how to make more chair vehicles like the ones in the vehicles menu (Chair, large office chair, airboat seat, etc) because I can't find them anywhere in the sandbox gamemode files.

Also, is it possible to make multiple seats with one prop, like a couch with three possible entry points?

Additionally, how do I remove certain entities/props from the map or spawn props/entities frozen in the map when the map loads?

Thanks for the help!

Also, as a last note, would it be possible to make a concommand that gave you a duplicator-like ghost at the mouse cursor (the context menu cursor) and a VGUI menu with only certain props in it, and then allow you to spawn the props frozen at the cursor position by clicking?