I already had turn downs so I didn't have to worry about the exhaust. Can't help you there.
It rides fine, even with stiff springs, 500#F/350#R at one time, 850#F/300#R now (SLA front end)
It will hook with decent tires on the rear....1.5 60', first and only trip to the drag strip with the big'n littles and only three passes.(30*-40* temps out side also).
I daily drive mine if the weather is nice, take it on trips, take it to The Dragon on occasion, drag race it, whatever I feel like doing. It does decent at all of them.
I got the severe duty TA, I knew my power levels would increase over time and I like to drag race every now and then, I wasn't taking any chances.
If you go to coilovers, get a shock that can handle it. Some can't support the weight of the car. Konis or Bilsteins are usually recommended.