i like their concept, though i suspect the party will not last forever
if he reaches a volume that will trigger some alarms at banks, they will start to ask questions.
i would advise them strongly to register a British LTD and get a basic payment provider license soon (some paperwork+700 pounds)
Is what he is doing any different from what BitStamp is doing? Or is he more lax with customer's identities and more likely to support money laundering?
Why should he deal with British law? He could just as well be a provider in any EU country.