I'm trying to remember, I think in Texas there are exactly two traffic violations for which an officer has to give you the option of signing a promise to appear. For all others, as far as I know, they always have the option of arrest instead of cite. There may be case law that restricts them more than statute, though. Someone has eluded that something like this was the case, but I couldn't even begin to validate or cite any supporting evidence.
I think the two listed in statute for which an officer must offer the option to sign a promise to appear are speeding and open container violations.
If I am correct about this, it is just one more thing to add to the long, long list of things that need to be fixed in Texas statutes. I mean, do we really think an officer should be able to, at their "discretion," arrest a person for something like their blinker bulb went out and they didn't know?
Edit: Regarding not answering questions, or asking your own questions, I guess your mileage may vary. I've "refused" (making an effort to be quite polite about it) to answer questions once during a traffic stop, and received just a warning. The officer suggested that it took him off guard a bit, but he didn't consider it rude or hostile.