You can probably cope without maths and physics but as a huge part of the course is studio work some art base would be helpful. Uni's will ask for a portfolio to show you can draw and be creative if you don't have an A level to tell them.
We do quite a lot of sketching and model making so try and include this in your portfolio.
You can still get on the course with any subject if you get the grades they want. With architecture being so multi-disipline you can do whatever mixture you want.
I don't think there is that much gender inequality numbers in my year are m/f 50/50 to 40/60, yes the industry is not at this level but I don't think there is a big issue.
The 7 years is a long time but the BA course (part 1) is 3 years and then you can choose if you want to continue. With architecture giving you a broad range of knowledge there are a lot of other job opportunities if you change your mind.
The course at Sheffield is 1 day lectures and 4 days studio, with workshops in cad, drawing and model making during the week. Studio work you get one project at a time and each project is designed to teach you a different aspect of architecture and its a mixture of group and individual work. You are expected to make a sketch journal through the year which is a mixture of project work and non-project work. Studio work is always different, you make lots of models to help brainstorm and design which is really fun. Lectures are on History, Theory of Arch. and Science and Technology they're normally pretty good but it depends what subjects you like.
I don't know much about the landscape course but dual students do both sets of projects (obviously shrunken down a little) so it's probably more work and you'd need to be quite organised to do it all!
If theres anything else you want to know just ask!