Well, I know that you can prune the burning bush. They are hard to hurt. You might consider eliminating it, since it is an invasive shrub here in Ohio,just like privet and honeysuckle, although I understand that fall color is hard to beat. Some viburnums make good substitutes.

You can trim back roses now but not much later because if you stimulate new growth in fall, it makes it harder for them to survive winter, I believe.

Cutting back lilacs now will probably eliminate next spring's flowers.

I don't know about the cherry or plum.

Good luck!