With regard to the whole weapons floating on backs thing, I think the reason people have issues with it is a kind of immersion uncanny valley effect. A lot of the stuff you mentioned Rag, are big, obvious diversions from our real world. Dragons as they appear in the forgotten realm don't exist in any capacity in our world, nor do Githyanki, or other stuff like that. They're so far removed from reality that they bear only the slimmest relation to reality, so it's easy to just shrug it off as simply functioning under rules that don't apply in our world. Specifically, magic. Meanwhile with the floating weapons, those are adjacent to our world. It's something that's not even trying to explain itself as a rule of the world, but it's a thing close enough to reality that it's easier for people to notice that it's a deviation. People register it as TRYING to immitate our world and failing to. At that point though, people need to accept that it's just an abstraction. It's not an in-universe thing that's occuring. In universe the characters are sheathing their weapons in real sheaths and scabbards, but technological limitations keep that from being portrayed on screen. Just like hitpoints are an abstraction that's not reflecting the reality of the world. So Rag, I disagree with you suggesting that it's an in-world thing that's actually happening and it shouldn't be treated as such, because I am certain that in the game people will say things about sheathing swords, etc, which shows that those things exist and are used. But I agree that it's ultimately not something that should be treated as an issue. As has been said before, this is down to a technical limitation, one that bigger studios than Larian have tried to address.
They don't understand why being able to "burrow" into a cage that's hanging twenty feet above you in open air is a problem, or why it breaks immersion, or why you should not be able to do that. That's the problem.
Is it? O_o
I know you dislike this attitude but still:
If its a problem, and its so "immersive breaking", and immersion is "so important" ... why would you do that?
I will say that there is a reason why in this specific example your argument doesn't hold water. Because for a lot of people, even if you don't actually choose to do it, if you KNOW that it's possible, know that the reality of the game allows for it, then even if you don't do it, the knowledge that the game allows for that will break immersion. Because unlike some other things, it's not an out of world choice that we the player are making to engage in an abstraction, it's a thing we are conscious is possible within the rules of the world even though it breaks the otherwise established rules of the world. I can get why people would be bothered by that and they aren't wrong to be, even though I personally am not bothered by it.