Re: dry. I’m convinced PLA doesn’t care about moisture. Watched a video of a guy that soaked a roll in a tub of water overnight, then printed off the roll with it still in the tub. Looked exactly the same as it did before the soak.
Mileage may vary of course but ever since then I’ve been leaving my PLA out and it’s never once given me trouble (the infused ones a little bit).
Someone else mentioned gridfinity, that was my first thought too. You can probably find modules for all of the things you listed already made and ready to print.
Once you start with gridfinity, though, you will never stop.