The only thing that I do that I didn't see you mention was clipping off your MIG wire with a pair of side cutters each time before you start your weld. This gives the wire sharp edges so that it penetrates right away when you start your weld. It also gets the amount of wire sticking out to the right length (I shoot for a half inch) before you start your arc.
I hope this is helpful.
regards,
Steve
New Orleans
