Reply to part 2 of your post
"If I do fail, (touch wood!) can I go to Switzerland and get a JAA class 1 over there? Would I have to declare that I failed over here and would it restrict me flying GB reg aircraft? Is a JAA class 1 as simple as that. Once you've got it, irrespective of in what country and after a few attempts you have it and it's job done? "
Regarding failing - cross that bridge when you come to it! You can take the test in Switzerland. Make sure they are aware it is for a JAA licence, and you should bring the results back to the CAA and they should (!) accept this as a pass. Many have done so, therefore I see no reason that they cannot accept this. You will not be restricted to flying any aircraft. As far as I know, it is considered job done.