By the way ----- I have to put a disclaimer in this thread and make sure everyone that's reading understands the nature of the relationships here. Charley loves me or he wouldn't put a "Weld sucks" icon as his picture... and I kinda sorta like him -- oh hell -- I actually respect him... and we have a blast together at the track etc. Ditto Gaetano... 
There is NOTHING WRONG with the Mustang. Nothing. I don't want anyone to read into this that the car isn't sorted or really well squared away and needs some fixing. It is - as Charley says - faster and more capable than most of the cars we run with. I drive it like a baby - because I'm still new at this... and quite frankly -- I don't judge myself or the car by how many people I passed "this session". I really just don't care. I have a sh!t eating grin when I get out of the car every session. 
I'm doing the things to the car for a couple reasons:
I want to drive easier and be faster going easier. 
I want 1/4 in the Mustang - handling wise - that the little Lotus has. 
Unless you've driven something like the Lotus on track you won't really comprehend. That little POS is just a master at handling. That makes it fast(er) because you can just kind of sit back and let it flow. 
My driving style is perhaps a little on the "aggressive" side once we get all warmed up and get going.... I have the power to close gaps rather smartly... a couple times almost a little too smartly... and while the brakes are okay (fine) - I'm looking for more of the "tap" and you're hauled down right now. I make a lot of driving mistakes out there... it happens... we aren't doing that many events that you get comfortable. I'd like to make those mistakes a little more forgiving and a little less oh sh!t. I'm ADD (truly) and it's not hard for me to be distracted and throw a late downshift - or go Oh hell... I'm off line... and need to reel it back in. I totally get that I'm not "the Stig". 
A car that is more capable than the driver allows for some wiggle room.... which makes it more fun... That's kinda what I'm going for. Some wiggle room for now.... and when the seat time gets more mature... the car will be something that's more than just "fine" but keeping in the confines of what we are doing and the other guys we run with.
Hope that makes sense.