If you work out a way to suspend your tarp over the top of your caravan without it resting, that is your tropical roof sorted. Or at least that's my understanding of what a tropical roof is.
So far as attaching ropes to your tarp. I presume you dont want to just tie a knot after feeding the guy rope through the eyelet?
It would get pretty messy if leaving them like that, and a pain on packup.
I am not sure carabiners would work well though, the cheap, non climbing ones cant take much load in my experience and the dear, climbing ones are too dear and good for this purpose.
You could get these:
https://www.tentworld.com.au/buy-sale/boltan-tarpchoker-25kg-6-pack I'd permanently attach these to your guy ropes and then use these to locate onto your tarp wherever you like. They dont use the eyelets of your tarp, but are relocatable and fairly easy to attach to the tarp.
You will want to be careful when creating this setup though. To make sure you're not creating great places for water to pool on your camper. It could be good to perhaps have one pole in the middle up high and then sort of A frame it down from there. This would give the 'Tropical Roof' too.
Not sure if I'm on the right thought path with this one or not. Sorry If I'm off on the wrong direction!