Yup, these updates help make sure your gpu still works with each os update, as well as maybe fixing a bit of uncaught issues/bugs

You could learn soldering, mouse switches are super beginner friendly and they cost about a dollar each (not including the tools)

That way you can buy a nicer pair and not have to worry about it breaking

Yes and please make sure you get it checked out! It may seem like a non-issue (just minor pain, etc) but if it ever gets worse the damage is likely going to become permanent and your quality of life with no teeth/extreme toothache is a lot lower than you might think.

Source: my dad and uncle neglected their teeth and its becoming a bad issue now