2. DFW metro is decent. You might look as far as Tyler (east) to Weatherford (west) and Frisco (north) to Burleson (south). Weather is a lot less muggy than Houston. You get more trees and greenery in the east; more hills as you go south towards the hill country region.
3. Economic stability is strong in Texas. TX never saw the housing boom in full effect like FL, CA, and AZ. Dairy farmers are hurting now, natural gas is coming down from a big boom on the Barnett Shale. I hear about folks getting new jobs and homes are selling.
4. To help make your decision, visit a number of places - spend a week or two visiting the different cities and regions. You might find that you like one of the smaller towns in Texas....some of the best kept secrets in America.
To back up something that HonkeyTonkMan said, if you head outside of the major DFW Metro areas, to Tyler for example, your cost of living drops dramatically. For example, a $250k home in Dallas proper would run about $175k in Tyler and $150k in some of the smaller towns around there like Lindale.