We moved from Austin in January. My son, who lives and works in Austin as an audio engineer, is visiting us for a week (we currently live in Hawaii due to my husband's job), and he's sitting on the couch here. I asked him your question. Here are his answers and my input.
1. There are no tornadoes. There can be flooding, but it's mostly limited to places that are quite obvious, like vacation homes on the rivers or lakes. We lived in an apartment that was not directly on a lake or river, and we certainly had some downpours, but no flooding. The flooding damage in the past two years has been limited to where you might expect it. A house was swept away, but it was completely overlooking the river - they had built the deck so it pretty much was above the river. So the flooding thing is pretty common sense. There can be icing sometimes in the winter. As a northerner, I found it hilarious. Several times they closed the city offices, government, schools and roads, for what I considered a minor event. I posted a pic on Facebook of the dire warnings and closings on the tv screen, and then a pic of me picking one small leaf off my car, with a couple of cold rain drops on the windshield. Everyone panics. If there is ice, just avoid the bridges and overpasses - not because you'll slide off, but because some clueless guy will be skidding all over the place, having an anxiety attack because the temps dropped to 37 degrees for a few minutes.
2. There's no fracking.
3. Culture is food friendly and music friendly. The food trucks are AMAZING and they're everywhere. Torchy's Tacos for breakfast will change your life. For the better. Every street corner has musicians. If you live downtown or in a music venue area with lots of bars, plan on hearing music from every store front. We found it to be very friendly. It's lots of young people. My SIL and my niece visited me (SIL and I are um. middle aged, niece and my daughter are early 20s). SIL noticed that she and I seemed to be the oldest people out and about. Lots of college kids (UT, St. Edwards, Texas Institute for the Deaf, etc).
4. Football football football. They're obsessed. Tailgating is a career for some people.
5. Traffic is awful. My son's advice: live near your husband's job. Mopac Expressway and other highways are among the worst I've seen, and we've lived everywhere.
6. Heat. Yup. But not anywhere as bad as Phoenix AZ. My son graduated from college in Phoenix and he said by comparison Austin wasn't so bad.
7. There are lots of nice things to do, lots of free events, lots of family friendly things.
Feel free to pm with other questions.