Any one more question regarding the paper pots :)

I have watched the tutorial on making paper pots and now have the method of making paper pots down to a fine art ! Can I grow any seedlings in the paper pots?
And basic question - do I use a propagator lid all the time - even if I am growing things in a 'plastic' greenhouse? And can/do I use a propagator lid over the paper pots?

Cheers