Cut the parking lot because it's flat and open and dumb and no one really likes going there and put the spawns in rooms or even in hallways.
I'd suggest that, instead of ridding off the parking lot, you turn the parking lot itself into a sort of serious layout (a map within a map), with cars and trucks as cover, and catwalks for people to fight in. THEN turn the hotel lobby or the bathrooms into the spawn rooms (after expanding it to fit enough people, of course)
EDIT: I'd also suggest taking a different approach on how the hotel itself is structured: instead of a flat, gigantic square filled with enough rooms to fit all robot masters and characters, please consider something along the lines of what the new Light Labs map is going to be in v5: each set of robot masters is a floor, and you can take elevators or the stairs to reach them.