That sounds really dodgy. You were absolutely correct not to even think about flying that aircraft. Fuel leaking anywhere is bad, but next to the master switch
. Also if the primer would not lock, the chances are that it would be allowing extra fuel into the carburettor causing a rich mixture, which could lead to an engine failure.
You said that the other C-152's were all sick too, doesn't sound like the maintenance is good at your club. Be careful
.