I hit the same point you are at a few months ago. I wanted to get my aluminum tent out and camp in it a few times with mock furnishings before deciding where to place the outlets, and finalizing my interior design. So, without interior skins, I have gone to a couple of rallies, a camping trip or two, and have probably logged over a thousand miles. Have not observed any damage, or anything to cause me concern.
I do not believe that the interior skins contribute materially to the structure of the shell. When you observe the spacing of the interior rivets (and the fact the they are pop rivets), it is improbable they matter.
I do recommend that you fasten down any furnishings you put in place so that no futon frames or the like slide around and dent your shell from the inside.
I started a thread asking for folks to share their aluminum tent interiors--failed to post what mine ended up like.
Anyway, good luck!