I have a Rolleiflex K4 (K4B?) and a Rollei pano head. Yes, you can put the pano head on the Rolleiflex K4. No, you don't need to, and it could be kind of a pain when not taking panoramas, because it places the camera weight well behind the center of the tripod mount. Of course that's the point for pivoting panoramas, but the rest of the time it's extraneous.
The Rolleiflex can be mounted on a tripod just fine; the idea that this is a fatal flaw seems to be one of those Internet legends. If one uses an overly long tripod screw and tightens it down like a gorilla without looking at what one is doing, the bottom plate could be bent. But if it isn't bent now, just use it and exercise the same caution you should when tightening any screw - don't overtighten, if something won't lock down, that's a sign of error.
BTW, mine requires a 3/8" to 1/4" thread adapter.