Yes for sure, Aeration damper are included in the R. I have bought 3 so far so this is 100% true.
7.5 should be nice indoors for beginning
I never raced indoors but heard that on carpet people like the Schumacher Mini Pins in the yellow compound a lot. Donīt know this for sure though.
What i forgot is no matter if you buy the DB01R or Baldre or Durga you will need a hex screw set as the Phillips type screws are a pain. Here is a screw set on ebay:
http://cgi.ebay.at/Schraubenset-HOCH...item2eaa50b9f9