My red flags:
1. Extreme (far left or far right) political views are a big no for me. I'm a moderate who likes some things from each side of the political spectrum.
2. If you absolutely hate history/historical places, that's a big no.
3. If you hate cats, then the date would be over quickly.
4. If you hate my religion and would not let any future children be raised with those views (whether they follow the religion when they are adults would be their choice), then that would be a no as well.
5. If you would ban watching soccer in the house, that would be a big deal breaker.
6. If you are divorced or separated (especially with kids in a custody situation), that relationship would not last long either.
7. If you have a criminal record, the date would end immediately.
8. If you never want to have kids, that would be a deal breaker too.