Jerky throttle : replace switches (?)
Slow start : Replace in tank pump. ( Main is new as is Fuel pressure regulator.)
Slow battery drain: Ammeter.
Replace Catalytic converter ( buzzing), O2 sensor, for general tune up.
Yes, no. The sensitive throttle, trailer hitching, is aggravating. Could leaky injectors cause slow start ? No smoke.
Sometimes backfires, crackles, reving up to closed throttle. Idles nice @ 850.