Well, no one is denying that the camera at the high speeds should perform on a frame by frame basis well, it should, especially for negative film and it's latitude (if you really want to see if those high speeds are accurate shoot a roll of slide). But the slow speeds and the self-timer issues indicate problems a need of service, sooner rather than later. You asked if you paid too much. IMO, you did.
Have you seen this Rolleicord price guide?
As it says: The price ranges shown are the approximate amount one should expect to have to pay for a Rolleicord in excellent, but used, condition. Camera should be fully functional as a classic camera with a mostly clean appearance, showing light signs of use or age.
In my experience getting one at the lower end of those ranges without the issues you mention is entirely possible.