i did my interview about 5 years ago now. I think that they are still along the same lines.
I got asked all of the things that have been mentioned. I also got asked about low pressure and the way the air moves round it - anticlockwise (think antelope - antilow, low pressure, anticlockwise, learnt that at college!)
However with regard to being not prepared enough. The book they give you has quite a lot of information but there is also a reading list. These books are ancient but it is still possible to get copies. The people that have come for visits to our unit in the last few years all seem to be able to get hold of a few and i think that it is expected.
It is a really good idea as it shows motivation and also gives you much more in depth information. Read them before your unit visit, then anything you do not understand you can ask the controllers to explain to you if they have time. (or even may be post questions here)
Good luck guys!