The rough starts and black smoke when starting warm/hot says leaking injectors, or leaking fuel pressure regulator. Pull the vacuum line at the regulator and smell it. If it has fuel in the vacuum line the regulator is bad.
You can rent a fuel pressure test kit for free at an auto parts store. Test the pressure at key on engine off, while idling, at 2000 rpm and the pressure drop when turning the engine off. The last at 5 secs, 15 secs, 30 secs and 5 min after turning engine off.
The test kit should include instructions that you can follow.