I suspect that the new growth on your holly bushes was damaged by the combination of frost and wind. New growth can be quite sensitive to environmental problems. Not to worry, though. The hollies should push out some new growth that will be normal.
The small white flowers would be attractive to pollinating insects, so it is normal to see insects on the plants when they are in bloom. Many holly species have separate male and female plants, and need to be cross-pollinated in order for berries to form.