I have direct flights on an A fare both ways MCO-LGA. If there are available seats in FC on an earlier flight 3 hours before departure, can I do a SDC to get FC? I know that A fares are not really FC, but a rather a Y-up from coach. How do A fares work for SDC?

Even if I don't get FC, if I do a SDC for a flight with connections to get more MQMs, are the MQMs still at 1.5 times the miles flown?