1) Route suggestions?
You’ve likely got your own favorite ways to get down to RCP, though Piney Branch-Aspen-Sherrill Drive, or Piney Branch-Rittenhouse-Joyce, looks doable. The challenge is on the other side. The simplest is to ride Beach down to Tilden (hopping on the trail for the stretch from Broad Branch to Pierce Mill). Then climb the gruesome hill there, and you’re only two blocks South of UDC.
2) How safe/available is bike parking there?
It’s a pretty safe area, though with lots of people coming through. I don’t think it’s a magnet area for bike thieves in general. There may be public bike parking in the lot under the Giant across the street.