@VEGAS702 
The Tuscarora will top out at somewhere around 15 feet tall and wide. From what I can see in your picture, it is planted way too close to your house. It is a very young tree at 2ft tall or so.
Usually it is not recommended that you replace the native soil, but you can add soil if necessary. I do agree that problems could be from radiant heat and watering. Crape Myrtles prefer acidic soil, but with care will do well in most soils once established.
The Twilight will mature at 20 to 25 ft tall with a 10 to 15 ft spread.
http://www.fast-growing-trees....
http://www.fast-growing-trees....
Some general info on care
http://www.wikihow.com/Grow-Cr...
http://www.usna.usda.gov/Garde...
and a bit of area specific info
http://xtremehorticulture.blog...
I hope these help.
