I agree - I haven't yet had need to access the hinge bolts of our door. but I think if/when i do, I will try cutting the fabric wall covering and inner skin with a hole saw to get a socket wrench in, then making up some sort of (hopefully attractive) access plate to cover things up afterwards yet make future access easy.
Not sure what other folk have done.
I feel a bit the same about the way in which they have hidden the black/grey water outlet slide valves - seems it would have made more sense to make them easily accessible.
Truth to tell, I sometimes wonder if the negative aspects don't outweigh the positive aspects of totally enclosing the underside of the trailer.
Sorry to wander away from door hinges!
Brian & Connie Mitchell
2005 Classic 30'
Hensley Arrow / Centramatics
2008 GMC Sierra SLT 2500HD,4x4,Crew Cab, Diesel, Leer cap.