Hand luggage allowance would be a matter for each additional airline, not security. Security will not refuse to let you through because you have 15kg of luggage instead of 10kg, nor because it's in two bags not one.
They may refuse to let you through with your knife that you used to catch dinner, the same as they'd refuse to let anyone else through with it.
If you want to go down the route of a handling agent, I'm sure Blackpool would not have a problem with it. Your fellow pilots might not be very happy with you though.