reguarding:
"Oh yeah... now I remember what I was gonna ask
could you plug a guitar into a line in on a soundcard? or would the signal level be different"

no, it's a different level

there are different levels of sound for instrument outputs, mic outputs, speaker outputs, etc.

you can't even plug a guitar stright into a normal soundboard

you have to get something called a direct box, which converts it to a mic-level signal

if you got one of those, you should be able to