I'd recommend having a layer of plate structures made of something akin to hydrophobic carbon nanostructures, with a layer of (Also hydrophobic) aerogel under that. This would allow for not only fireproofing and waterproofing, but also acceptable radiation-proofing in all but the worst conditions. It would also cold-proof him, albeit maybe not lava-proof, depending on the situation. And the lava would hurt regardless. Oh, and also make him bullet-resistant. As for aging, there are pretty efficient ways to stop that, with things like epigenetic repair, emergency metabolic shutdown, and telomerase.
The only problem I see is the black-hole-proofing. How does that work?
