Excellent guidelines. Especially the "Person A writing tests for Person B's code" one. ++
The test suite will run slower, and with 2,500 tests, that is going to become an issue.
To be honest, I am not really concerned about this, since its a rather large framework (almost 150 classes, almost 13,500 loc) and (for us anyway) its the foundation of our applications. It really has to be reliable for us, so even if the tests took an hour to run that would be okay for us. I realize this may not be okay when we get around to distributing this, but I will deal with that when the time comes.
Time spent developing unnecessary tests detracts from development of new code.
Thats just the thing, the tests run are redundant, but alot of them are in functions and therefore really didnt take anymore time to develop. Its actually saving me time, since I can re-use the test even though it is somewhat testing something I know is already tested (sort of).