Alright another Texan! Welcome to FABO--cool Valiant, looks like it'll be fun regardless of what you do with it. I would say if you were near Abilene, I bet I could find a pretty straight fender for you at FM600 wrecking...and if I were back in Texas...really miss home.
I don't think it'll be a problem...lots of guys I knew have their caged pseudo racecars tagged and insured in Abilene complete with nitrous bottle. That being said, if you think SA is more stringent on that, dismount the bottle for the afternoon, get it inspected and registered, then you can put it back in later. I heard something about Texas getting silly with the yearly inspection and registration nonsense, what all changed?