Go ahead and cut back the hostas and peonies. Do not compost the peony foliage. Dispose of it. As to the roses, leave them alone unless they've got really long canes that will whip around in the wind. Those you can get back somewhat.

Unless you're in an area that gets icy winds from the Gorge you probably don't need to do anything to the roses for winter. Plan on pruning them in February, I think that's when the Portland Rose Society advises pruning.

Up here we cut the roses back in winter to reduce the amount of 'sail' they present to the wind. They will literally blow out of the ground up here, but I've never seen roses do that before moving here. It's the gravelly waterlogged soil and the hurricane-force winds that do it. I think in Portland area your soil will in general be much finer textured and less likely to let go of the roots when the wind yanks at the top of the plant. Wet gravelly soil has no cohesion, so there's nothing for the roots to hold on with. Wet loam or clay won't have that problem.