MustangForums.com - I'm having choppy idle. just replaced coils and plugs. any suggestions?

Hey guys, so I'm having choppy idle and it feels like it is running a bit rough.

I had an upper knocking. I believed it to be the lashes. Sad to say, due to finances,I just ran with it.
She broke down and I had her towed to by my friend about 4 months ago. He did some pretty basic stuff.
Changed plugs to Motorcraft ones in.
Changed the fuel filter.
There were other things, I just don't recall.

He got it up and running again. It still had the knocking but was running.
About a month after, my dash went crazy. I lost power, the oil pressure dropped and it idled very rough. I decided to take it to the mechanic this time. They said my timing chain guides and tensioners were shot. Plastic and metal in the oil pan. the chain was eating away at the timing chain cover and also ate into part of the oil pump. $3000 later, they fixed it for me.
Fast forward to now, about 3 months after that. I got the flashing check engine light,(misfire code. don't drive it) so i pulled over and inspected it. couldn't see anything or hear anything different. so i decided to drive it to work and back home after.
Took it to the same mechanic hoping the work was under warranty and I wouldn't have to pay.

They did the Diagnostic and said that the 8th coil was bad. So I looked up how to change them and its sooo easy. I decided to buy MSD blaster coils. I just replaced coils last night and it runs. I haven't gotten any codes yet. But it is still idling rough and struggles a little on acceleration. Also on the driver side there is a weird air sounding noise that I didn't hear before I changed the coils.
Oh also, I found out that the coils are not secured on well. Someone has stripped the threads. Tips on that would be great too.

Thanks,
Sam