Yes those would be good to have, but I imagine both quivers and weapon sheaths would require a fair bit of animation (how they move with the character during a walk cycle, etc). I'm sure they could do it if they wanted to.
I said it when the early access was just starting and I'll say it again: as a compromise I would be fine even with doing it "the cheap way" with weapons that are just "teleported" out of the sheath/scabbard in the hands of the character.
It's not like now it's particularly more elaborate to begin with and it still beats having "naked" weapons floating glued to the back of the characters, which by the way is particularly ridiculous for short weapons like daggers and short swords and it's so tragically "early 2000" in videogames standards.
LOL, yes. Annoying as an archer, but I understand it from a visual/design point of view.
I'm not sure I do, frankly. It's not like it looks better. It makes playing an an archer/crossbowman feel... lousy, for the lack of a better term. It lacks proper "kick".
I genuinely think that "mechanics" aside, it would look better to have projectiles moving in a (mostly) straight line and a bit faster, too.
Incidentally it would also (once again) match the rulebook better, since projectiles' lines of sight in D&D are in fact traced/calculated with straight lines from marksman to target (especially given the short distances involved here).