Well thought out...
Walter, good question. If the guy is 7' tall, it would be a problem and I've placed a fire extinguisher to the right and a hose sticking out the back so you can rinse off. The burner exhaust is well above your head and if you'll notice, it's above the hose reels so it's not somewhere you are going to be walking unless you are walking on top of the hose reels.
Is that well thought out?... oh and no holes in the trailer with some makeshift vent pipe sticking out the top. Now you can back it in your garage door in the winter.
Last but not least, it works and works well. If there is some better way of doing it, I want to know. I've been looking for the right vent pipe out the side or out the top that would allow clearance for overhead obstructions. The side sounds good but want something that looks nice and that's washable. I'm open for any ideas.