You guys are awesome! I really appreciate all the suggestions. I didn't realize I could get European hinges for thicker doors. And already bought the 3/4". The biggest issue for me is the fireplace and the wall of windows opening to the river. Just seemed like a recipe for disaster. And the boards have already started to move a bit. Since yesterday about 1/2 of them are now not perfectly flat.
I reached out to my uncle in law that has a commercial cabinet shop and he recommended veneered MDF and said that was awi compliant. Anyway, I think I'm going to sub this out to him and remove all doubt. Thanks again for all the suggestions!
an excellent plan!