If my waveforms aren’t symmetrical, is it usually the fault of the soundcard? I can’t see the mic causing that.
Is this a major problem-causing error? So far, I can’t discern any audible problem. Just curious!

Win 10
Asus computer

Try removing any DC offset per the instructions here:

We have noticed that it is not uncommon for voices to be “unbalanced” as you say, if removing DC offset doesn’t make any visual difference I would say “Don’t worry about it, it’s Normal”.

If there is a shift then it indicates a small fault in either your soundcard or your preamp (but more likely the soundcard). If the offset is small I wouldn’t worry about.

Post a sample and we’ll have a look.