@Draekos Look up wincompose! It lets you type weird characters easily and in a memorable manner (instead of windows' default alt sequences, which are garbage). You can remap one of your existing keyboard keys to what's called a compose key, (scroll lock is a common choice, but I used the windows key) and then type characters like ö as compose-o-". Because alt↓-1-4-8-alt↑ is unintuitive and hard to remember.
@Draekos Most (all?) distributions of Linux have this behaviour built in (part of X11 I think), but you typically have to go enable it. I thiiiink you should be able to enable it on OSX too, because of how much it shares with linux (more than you'd think!), but don't quote me on that.
@Felthry I have no idea what that means. but yes that seems important!