You are relying on a couple of 1/4" hinge pins anchored into plastic on the handles to hold your Pelican. That doesn't look very secure to me.
It's more than secure. Especially since the contents of that particular pelican are relatively lightweight food items, secured to two separate handles (3 possible). The handles are way overspec'd. They aren't going to break.
I like the Pelican because it has the handles for tie-downs, a hinged lid that can support itself vertically, when open, has wheels to roll the case to the vehicle from the kitchen, and will stay shut in case of an accident. It works better than any of the cheap cases I've used from Lowes or REI.
I also don't understand why a case needs to be waterproof when it resides in a vehicle full-time. But that's just me.
It doesn't need to be waterproof. As described above, the case is very functional for other reasons. I think the reasons above stand on their own, but I do use this case for more than just this purpose. you'll notice that it is removable in a few seconds via the Mac's Tie Downs.
Does the right hand drawer open when the table is folded down?
No, and it wasn't by accident. I stored tools and recovery gear in the right hand drawer. I've never needed recovery gear when eating. The left hand drawer stores a cutting board that can be laid across the top to create extra counter space if necessary.
I don't see any clothing or water supply in any of those photos? Firewood?
That's because we're nudists who fast when in the woods.
The clothing goes in a variety of places depending on how many people are with me. we use duffel bags as they are easy to get into from the top. I either store them on the backseat, or in the left wing between the fridge and window. Both locations allow the fridge and pelican to be opened quickly and easily for a quick meal without requiring us to unpack the rig. The smaller camp chairs are stored on the other wing (to the right of the Pelican) so we can set them up and store them easily if we use them during lunch.
Like you, I live where it is wet. I don't usually carry more than 2liters at a time and then use a water purifier to refill. For desert trips, I have tie downs on the back floor where I can secure up to 4 Jerry cans going across (with no rear seat passengers) to Land Rover Genuine Tie-downs secured to the seat bolts. At 40lbs each, and so much weight behind the rear axle already, I prefer to have the liquids low and between both axles.
I don't usually carry firewood. I have an axe that mounts between the fridge/pelican and the back seat. I have a chainsaw that I carry on the backseat floor (lashed to the tie downs) if we are expecting blow downs.