Yeah, Serpents are VERY rare—I've only ever come across two in all my playtime. The scales sinking is a massive pain in the ass but at least the meat floats. The thing with Serpent drops though is that they are all pretty optional—the food is great but not mandatory and the scales only make a tower shield which suck compared to parry shields.

Silver, eh, the hardest part about that is getting it back down the mountain and boated off to where you want it. The nodes are easy to mine once you find them.

Iron, get used to mining crap piles in the crypts. Really used to it.

Fishing, well, I've got lots of fish stockpiled but it does take time. I really think fish should drop 2/4/6 pieces per catch quality instead of 1/2/4, that'd speed it up a lot.