I understand why they added Wilson to the script and I think it was necessary but I am not sure I would do that myself.
The cave makes sense initially but he never really improves upon it. I guess I am thinking of all the stuff they built on Gilligan’s Island (which was fictional of course). It just seems like he should have built more stuff…perhaps build a hut, a bed frame, table etc. inside the cave.
Also, he was there four years. He could have started building a raft in the first month and had a much nicer raft than the one he used.
I still like the movie. I just think if it were me I don’t think I’d have a Wilson and I would probably build more stuff somehow.
I don’t need a Wilson. Or rather, everything is a Wilson for me, even if I’m not castaway, and even if it lacks a face. See those three trees there? They’re now Nona, Decima, Morta. That huge rock? He’s Ozzy.
In his situation I’d probably do the following, roughly in order (it depends on pressing matters):
I wouldn’t build a raft. It’s simply too risky, I’d rather live poorly in an island than die gloriously in the ocean.
Regarding the wall/floor smoothing, it’s mostly for security - to give bugs less room to hide themselves. Ideally some makeshift concrete (mostly powdered clay and seashells baked together, and then mixed with water, small stones and straw); but worst hypothesis just some mud on the walls.