Doing Physics and Maths Msci Joint honours course.
Physics is a good department imo. I've never really felt the need to use any of the services offered aside from lectures but generally everyone is pretty approachable, has plenty of office hours etc.
I think the workload is fine but a few people complain (this will always be the case though :P). The exams can be a bit painful though, theres a lot of them all at once and they are pretty much the only thing that counts towards my marks.
Research areas will basically mean jack **** to you as an undergrad. Some people like to talk about how its nice to be taught by leaders in their respective fields but in my opinion thats a load of rubbish. Even by the time you have graduated you will still be relatively clueless and the material will still be basic compared to the actual research going on (this is true of all universities) so it's much more important to be taught by good teacher, something which I believe Durham has.
That isn't to say that Durham doesnt have talented researchers etc, the Physics department is really strong overall. Off the top of my head, AtMol is a strong group and the IPPP is meant to be really good too (as well as astronomy which you already mentioned)
Male to Female seems roughly 50:50, I certainly havent noticed a lack of gender diversity at any point.
Not sure about jobs really, it's pretty varied so you probably aren't going to miss out on many opportunities