Okay.

Why does my thread come out of the top needle every so often? Is it just cos I don't have enough spare thread pulled through? I've done it on a few different tensions, so I don't know if it's a tension issue. Or is it just the result of having a cheap machine?

With tension...what do the numbers mean? My manual's in a sort of translated English so it's a bit tricky to grasp.

Do most people press things like hems before sewing, or just pin them?

That'll do for now.