You surely can! Now is a great time. I cut mine back regularly in a "natural" style - I cut some today, and will cut more again next week...this keeps them in a more natural shape.
Lorapetalum are a great shrub to practice pruning!

Yes, I try to do the "natural" thing too, but wow! they sure have gotten big!
So even if I cut them back now, they will still get enuf new growth to bloom normally next spring?

Yes. Mine bloom over and over again and love it when I cut them back. PLus it rejuvinates the leaf color.