Don't be too discouraged from your project. I don't think the condenser would burn out being installed in the storage compartment, unless it had some sort of manufacturing defect to being with.
Problem I see is all the heat it will dump finding it's way back into the RV living space. The pass-through basement in my RV is constructed of stapled together pieces of 3/8 OSB, not insulated or sealed at all. The basement is essentially "indoor" space that was covered up from the inside and then they put doors on it for the outside.
How is your basement constructed? Can you bolster the construction to seal it against air leaks and insulate it to keep the heat out?
Check out this blog, of an old bus converted to an RV. The owners installed a mini-split in a basement compartment, as well as separate air conditioner to cool their battery bay.
http://www.beginningfromthismorning.com/
