Yup - ignore knowing you are in restricted airspace or within 1 mile of a nuclear reactor. Or that, when you drop the copter on the M4, you'll be politely asked about your insurance.
Whatever you do, definitely don't make sure you know how to operate a flying lawnmower safely and how to pilot it when all your electronic aids go tits up due to some bozo operating a WiFi repeater at 1000watts.
Most of all, don't worry about the 400ft legal restriction the CAA slap on all UAVs or SUSA (to give them the official designator). Why would you want to be concerned about smacking your craft into an aircraft ... what's the worst that can happen eh.
BTW Sir .. did you know you are flying in an area with a NOTAM on it? Those men in black suits want to have a word as you flew your craft in a very sensitive area and they really don't have a sense of humour ....
And no, the CAA are not about to lift the restrictions on commercial SUSA use (though they are looking to be a bit more sensible when your craft is under 7Kg).