The inside of your trailer looks so much like the inside of Peanut we're a little disoriented.
However, it would be reversed from what ours was...
You do need the upper vent; it needs to work. You need a range hood if you are going to have a propane-burner stove in there.
We took out all our appliances except lights
, and Paul was therefore able to remove both of those vents.
BUT...he also spent many hours fiberglassing over the holes, taking great pains to match what was already there. We painted the entire outside when he was all done patching (over 85 holes and cracks in the fiberglass).
Can you post a picture of your whole trailer? Paul and I can't get over some of the details that look so much like our amerigo!
But since you are putting in all new appliances, you'll need all your vents. The roof vent won't handle venting the cooking oils properly. They are heavier than air and will fall
as soon as possible before your roof vent can carry them up and out, and your whole trailer will be greasy inside, eventually. You don't want that. ALSO, and equally important, a range hood is made of metal, and will not burn. The underside of your upper galley cabinet is made of wood, and WILL burn if something flares up--and food sometimes does flare up.
1st picture: door side of Peanut showing both vents--upper one was for range hood (we took range hood out).
Lower one was for the range, oven, & furnace (we too that out, too).
2nd picture: our galley rebuild in progress. We used the original lower galley frame--note it is reversed from yours.
3rd picture: door side of Peanut showing where the vent holes were fiberglassed over. Paul laid in two fiberglass panel fills to make the "swoosh" design on the side.
4th picture: the original galley when we bought Peanut--showing range, oven (furnace was inside oven), range hood and sink in place. We gook it all out.
We put none of it back in--or we'd have kept the vents. They are important.
Does this help at all?