Chiming in with more eager newbie questions...
Am I correct in saying that you don't need to mug at betting exchanges? As they make money from commission I was under the impression that they're not bothered why or how you're betting.
Also, regarding gubbing- how cautious do you need to be in terms of using the same username/email? I'm currently using the same email for exchanges and bookies, but (mostly) different usernames, at the moment (and not the same username/email as on matched betting related sites). I've seen people advocating some very strenuous methods to avoid gubbing, like never following the links on matched betting sites to bookies, and having different internet browsers open to keep exchanges/bookies/MB sites separate, but am not sure how much of it's paranoia, rather than things bookies would actually catch you out with!