I have been through RAK three times recently and I am sure that checking opens 2.5 hrs early. The first time I needlessly sat in the concourse waiting for checkin to open because I did not realise that the BA desks was behind the desks in the main concourse, down on the left hand side. As CWS says it is passport control rather than security that may take time. As many have said the lounge is fairly basic. One tip is that if you have no bags to collect on the way in, avoid the queues in the currency exchange in the baggage hall and change money in the main concourse where there are also ATMs which I prefer to use.