Its a Gallica, thats for sure. But which one is hard to tell - there are so many lavender/purple/crimson types out there and many are unknown or incorrectly labeled. I suspect your photos may not represent accurate bloom color.

Again, hips? Does it mildew in summer? Does the bloom color change as it ages?

I only see evidence of a few hips from last year, my sense is that most drop off before setting. The bloom color does fade to a pale pinkish purple. There is some color variability between blooms and among the petals of one flower. The centers tend to be a bit more pale. Some petals are intense, almost magenta, and others are softer. On my computer the overall color in the earlier flower photos is less intense than in the garden, but these petal colors (from one bloom) seem fairly accurate. As for mildew, I cannot remember but I think so. I live in a high humidity area, so mildew and blackspot become an issue later in the season. Right now, the leaves look very healthy. Thanks again, your input is very much appreciated!