Titanium is corrosion resistant and need not be painted. Titanium is non toxic and bio-compatible- it is the primary material for implanted prostheses such as artificial joints.
Titanium is compatible with carbon composites, unlike aluminum.
Titanium is castable (using hot isostatic pressing- most aircraft engine hot section parts are titanium castings) and can be formed to very deep sections with superplastic forming (blown into a mold from sheet at high temperature).