Hi Erick,
The Catskills, cool! Beautiful area. Are you in Green County? We use to live across the river in Columbia county. If you drive over the Rip Van Winkle bridge heading towards Olana and sort of go right through that mountain...our farm was on the opposite side.
Now to your camper, this is the support place! Go Erick, Go!
I'll second to not use the silicone. You will not be a happy camper after a year or 2 and then your sort of stuck as it almost infects the metal to not all anything else stick. It gets into any little pit, etc and it becomes a bear to get it all out of there. Here is one product that you can use
https://dicorproducts.com/catalog/roof-products/replace/epdm-lap-sealants/
You can buy it on line, Amazon, Camping world etc. Even the local RV dealer should have it.
You can get the non leveling type and use it around clearance markers, vertical places etc. For windows and doors if the seal is real bad to the side of the camper, take all the screws out, pull the window and use butyl sealing tape and recreate a real good seal. It is some time, but not a lot of money and good the butyl sealing tape will now outlive the camper.
And you can get the Dicor off with a heat gun to warm it and then get under it and can take it off. Put some new on. After about 4 years, some fine slits may start pending the degree of flex, just fix them as soon as they show up, top coat over them or take it all out and put fresh in.
Everything on the camper is fixable. If you supply the labor, the materials are not that bad. We have had many reconstruct the camper and some build it new from the frame up.
We can help on how things are made, some options on how to get parts and how some have fixed theirs. This is the place for Sunline info.
Hope this helps
John