The atlantic coast is really nice too, and not far from Gibraltar. There are plenty of people who live in Tarifa area and commute to Gibraltar. It depends on what you like.
Tarifa is a port and tourist town, especially for kite surfers - so many bars and restaurants are seasonal. There is a bit of a bohemian feel to much of the town, but it also has a very traditional small town Spanish side to it. The wind is extreme at times. I don’t live there, but I visit often and stay with British friends that do. Like everywhere it has its ups and downs, but I think I could live there quite happily - as long as I had a nice house protected from the worst of the wind.
You would get by with English in Tarifa, but there is plenty of opportunity to learn Spanish.
As far as cats go .... my Tarifa friends have cats and it seems to work fine. They have a cat flap to their roof terrace and the cats roam where they want. Of course there is risk. If you want cats without risk, you can’t let them out - but that’s also true in the UK. As everyone has said in general Spanish attitudes to pets are different to British attitudes. That said I have a Spanish friend who worked for years in a pet refuge in Estepona and is VERY sentimental about animals - as ever, it pays to keep in mind that nationality isn’t the end of the story.