All lenses will have dust in them. If your can't see it just means you haven't got a torch that's powerful enough
It won't affect a thing, carry on using it as you were.
Yep- annoys me knowing it’s thereAgreed although it would annoy me.
Yes this is a concern as I will likely be selling in a couple of months (hopefully if I part exchange I might not lose out)Dust will negatively affect the resale value of your lens.