as far as your ability...I want to say I give you a lot of credit for taking the dive as a newbie on the M5. You picked a relatively complicated engine to cut your teeth on. I will try to give you some advice because afterall you listened to me when I suggested you shooch your motor forward to get as the cam retainer behind the head versus pulling the engine :-)
Your list looks pretty good. Sounds like you have time...a key element in doing the job right...not to rush. Machining that head will be a challenge Jason. It is for an experienced shop only at 4 valves per cylinder. Find someone who knows that head before you just send it off. As to cleaning the piston tops...check the archives...just do a search. Myself, Bill R and others have written adnasseum on the subject. Just be sure to flush both the cooling system and send at least a quart of oil over the valves with the valve cover off to not only lube the top end but flush out all the crud that falls into the engine before you fill it with fresh oil.
Good Luck,
George