1) Shift W(to wear), Shift T (to take-off, unwield)
2) you’ll need a watercraft: raft (3 trunks, 10’ rope) or punt (have to trade it) and paddle; or cut a hole in the ice in winter. Or you might be able to set nets from an tiny island, deeper in to the waterway.
3) wandering around looking for good spot is option too. As long as you have few wall sections to support couple roof&floor sections, you’ll survive. Fireplace needs to be built on floor. You can also squat in villages, as long as you behave.
4) correct, old age deaths, ailments, weakening, et cetera are not implemented.
5) no, not necessary. You can easily trade excess meat, fish, furs, crafts to villages and buy produce from them. You can also omit farmed produce altogether and supplement meat and fish with bog beans, lake reed roots, wild nettle, mushrooms and so on.
And welcome!
And if you plan on fletching/making your own arrows, you should stockpile berries as bird trap bait. Can’t trade for feathers and picking up dropped feathers won’t last long.