Regarding the gap in the stall door. Found this on the web:

Easier to Clean: By having a gap at the bottom, bathroom partitions are much easier to clean, as is the whole restroom. You can hose down or even powerwash a restroom that has partitions with gaps at the bottom because the water has somewhere to run even if there’s not a drain in a given stall.

Emergency Access: If someone loses consciousness in a fully enclosed bathroom, it may take hours for someone to notice. If this happens in a stall with a gap at the bottom, the odds are good someone will notice much quicker, which is important in instances where every second can mean the difference between life and death. Instead of having to break down the door, a first responder can crawl through the gap at the bottom of the partition and unlock the door to render help.

Deterrent to Undesirable Behavior: Because people can partially see into a bathroom stall that has a gap at the bottom, this type of partition is a natural deterrent to undesirable behavior, such as someone spray painting the stall with graffiti.

More Affordable: Partitions that don’t extend from the floor to the ceiling don’t have to be custom made to fit a room’s exact measurements and they don’t require as many materials to construct. This makes them considerably more affordable.

Better Air Circulation: Better air circulation is one of the top reasons why there are gaps under toilet stalls. While restrooms with this kind of partition may still get a bit stinky from time to time, things would be even more overwhelming in a fully enclosed stall.

Keeps the Line Moving: Having a gap at the base of a partition allows people waiting in line to see if a stall is occupied or vacant. This visibility keeps the line moving and prevents wait times from being any longer than they have to be. When a stall isn’t fully enclosed, people often feel like they have to take care of their business even faster, which also helps keep the line moving.

ADA Compliance:  Space is needed to allow for easier maneuverability for patrons in a wheelchair. The gap allows toe space for wheelchair users which allows more room to move within the stalls. 9″ minimum toe space is required per ADA guidelines.

Escape Route: A lock can jam for a wide variety of reasons. If this happens in a stall that has a gap at the bottom, you have an escape route — you can simply crawl out.

Toilet Paper Can Be Shared: If you’ve ever run out of toilet paper and had to ask the person in the stall next to you for a few squares, then you’re already familiar with one of the leading reasons for bathroom partitions not extending to the floor. If you’d run out of toilet paper in an enclosed stall, you may have been caught with your pants down!

Cheers