Ya, I got done with putting my haunt down on graph paper also. Since your maze is only 3 ft wide walkways there isn't much of props or anything that you can put in it. But maybe you could decorate the walls to make them look like different things and have actors stand against the walls with costumes that look like the walls so they can camouflage themselves in and you could give them some sort of noise maker to use. Things you could put on the walls might be camo netting and vines, maybe even some burlap/erosion cloth (cheaper). As for the kids seen maybe a bed and dresser (normal stuff) then at lots of creepy dolls and stuff. Check thrift stores they will usually have stuff like that. Then have clown actors and stuff, if you have too many clown props it will feel more like a fun house rather then a kids bedroom where maybe the clown are the kids nightmares.
Hope this helps