I'm glad to help. I'll handle your questions in order :)
1. The course is very intensive. We learn a lot of stuff very quickly and by the end of the first semester we knew enough to work in any department and possibly publish a book on our own. There are 4 mandatory modules, 3 (Editorial Management, Marketing management, Production and Design) are taken in the first semester and the 4th (New Product Development) is in semester 2. Everyone, regarding which of the Publishing M.A. (straight M.A. in Publishing, European, Digital etc) they're doing, has to take these modules. Then in semester 2, you also have to take 2 other modules that you get to chose (Digital Media, Rights Management, Children's Publishing, Magazines and Independent study in which you pretty much get to make up your own module etc.). The classes are half lectures which the Lecturer teaching and the other half is seminars or workshops in which we do some practical exercises usually divided into smaller groups.
The Lecturers are all great and very helpful. There are a couple whose teaching style is a little lacking but they make up by being happy to answer questions and see you in private if you need more help. It's fairly informal and we call them all by their first names, so you see, it's really very friendly. Everyone's here to learn so it's not a problem that we're so informal. Some of the lecturers are born comedians so their lectures are hilarious as well as informative.
The uni has a computer room just for publishing in the Tonge building with all the software used in the publishing business. We mainly learn to use Adobe InDesign which is the most widely used now. There's also Quark but if we want to learn how to use it, we're on our own.
2. The mandatory modules are for everyone and there's no limit to the number that can be. This means that everyone taking any of the Publishing M.As. will be there. At this time, that's about 75 of us. Of course, some people don't show up to classes and prefer to learn on their own using the lecture slides and the part-time students don't take all the mandatory modules at the same time so they're only there for one or two modules every semester. It sounds like a lot of people in one room but it isn't that much really and the lecturers are very good at reaching even the people at the back (I know because that's where I usually sit :D). For the elective modules, we're in smaller groups. There's no limit to how many people can be in one class but they're usual self-limiting in that there's many modules and people have different interests and goals so the main group breaks up into smaller ones. Children's publishing and Rights Management are the ones with more people.
3. I didn't find the classes to be too hard but they do demand a certain amount of work and, in my opinion, it's important to go to every class. It's not really possible to start your assignments at the last minute, for one thing, because a lot of it is group work. You don't get to chose your group so you never know who is more or less reliable. There's some maths involved in Marketing and Production which some people have a hard time with but I was terrible in maths in school but found it fairly easy if boring. Another possible difficulty is whether you can learn software easily or not, then there's the design aspect where some people are just naturally better at it than others. But I've seen everyone's Design projects and was very impressed by them.
4. I know that the City and Kingston programmes are good. City especially has a good reputation. I looked it up a bit because I applied there too. I think the difference is in how theoretical vs. practical the programmes are. Otherwise they teach more or less the same things. City is in London so that's one thing to keep in mind as well.
Have a look through my blog at http://publishingu.blogspo
I talk mainly about what I'm learning and doing and things like that. I'm not a very regular poster but there might be something that could interest you.
I'll be happy to answer any other questions you have.