Hi, im new to this forum so hi \o

Right onto my problems, just purchased a 2003 1.4 fiesta zetec se, from what i can tell i have 2 problems, first is a misfire that is definetly worse when cold, once its warmed anything over 2k revs the misfire disappears and revs up perfect with no holding back, then when i try to let it idle it will try to settle then switch back to firing on just 2 and 3 which brings me onto my second problem, the car refuses to idle properly although i did spray some carb cleaner into the throttle air intake and it idled perfect until i took it for a drive and turned off the engine........

ive changed coil pack, ht leads, fuel filter, spark plugs, where do i go next?
All help greatly received

p.s. obd reader codes giving p0351 p0300 which is something to do with coil A secondry circuit and random misfire.