I don't know of a "walkaround" to use the Black Rapid and a tripod mount. This is the only disadvantage to the Black Rapid. Right now I unscrew the Black Rapid mount on and off as I need to use my tripod. At home I'm fine with this, but when out and about it can be a pain switching back and forth.
Glenn, I have used my Black Rapid with a third party grip and a 70-200mm 2.8 and have walked around with it at my side. It rides well with out my hand on it, but most of the time I have my hand on it. It does make me nervous and I find my self resting the lens across my left arm to carry it. In the unlikely event if I were to drop the camera, the black rapid would stop it from falling to the ground. It all depends on how much "one" would want to push their luck, with me more than likely I'm going to carry my 70-200mm 2.8 more than I'm going to let it hang by my side on the Black Rapid. I only have had the lens a few weeks and I'm still experimenting on how I want to hand the lens while on the camera, it is a hand full.
Rick - I am considering the BR sports strap. However, If I am going to use a BR strap, I would use two medium or one heavy duty tie-strap to support the metal hook just in case it fails or slips off. I would also re-inforce it with the additional tether that I previously posted.
Flickr: Discussing Black Rapid strap in ATLANTA PHOTOGRAPHERS GUILD - Next Meeting March 6 @ Elliott St
Using the 70-200mm will normally require you to attach it to the lens foot. I am just not too confident risking such an expensive gear unlike the proven kevlar materials that the upstrap uses.