Here are the short version of the rules: A) You can ask for anything B) They reserve the right not to give it to you

If working from home on Thursdays is a sticking point, ask to work from home on Thursdays and get that in your contract. It doesn't really matter if it's because you want to spend time with your family/cats or because you don't like going outside on days with a 'ur'.

If you REALLY want a pony, ask for a pony.

(you're not likely to get a pony)