Starting issues never end.

[07powerstrokebosss]

Ok three weeks ago I had all Injectors replaced all were sticking and I was running full syn and rev x. Truck is 07 167000 miles, no mods just stainless pipe and intake, after getting truck back it ran excellent for four days then hard starts continued, batteries are a year or less old. Truck would start after cranking over a couple times, this continued since the shops backed up and Im not much of a mechanic, I changed all oil and filters drained water from frame rail filter. The ficm was replaced about 15000 miles ago and checked and ok when injectors were installed, today after sitting 3 days I tried to start it and it didnt want to crank well threw a charger on and it would crank but no start batteries still show 12.7v. After a few trys with it cranking it just quit and won't crank assuming the starter is now shot also or a relay or aomething, only cranked it maybe three times before it quit trying all together. It starts equally bad both cold and hot, no smoke at all until it fires (fired) up, then a puf of black and a little white till its warm, I park in a garage and plug it in usually if its below freezing unless I'm at work. Any help or advice would be appreciated I looked in tech and nothing really fit all my issues, on the upside atleast it finally quit in the garage at home and not on the road.