A few random thoughts for you:
1) Even if your bike uses premium I think your average gas price will be under $5/gallon in and near Texas.
2) It's hard to overstate how hot and humid it can get in Texas in July. For that last 500 mile leg consider leaving very early, and plan to get off the road by 2 or 3pm. Between about 1pm and 6pm in July is not a good time for a long trip in Texas, especially on the interstates!
3) I-35 between Dallas and Temple sucks the big one. Lots of construction, slow traffic, lots of two lanes between jersey barriers with no shoulders, dogs and cats living together, human sacrifice, mass hysteria!
Once south of Temple I-35 is not so bad as interstates go.
5) Remember that Davy Crocket is considered a Texan, and he only lived here six weeks.
Welcome, fellow Texan!!