So one of the inherent assumptions in poker is that you are always playing the strongest possible hand, and that assumption is also true in Card Drives. As a straight flush is stronger than either a flush or a straight, if you play 5 cards that share a sequence and are all in the same suit, that always counts as a straight flush.
Face cards can be used in a 3 sequence exploit. This is another inherent assumption in poker, that face cards have a rank that puts them in Jack, Queen, King order, and that order comes after the 10 card. So for example a 3 sequence could be 9,10,J, or 10, J, Q, or J,Q,K, or Q,K,A.