I believe the MVP/First Class line is really meant for AS elites and F, but its probably not a huge deal, especially if its a bit slow when you get there.

For the Ecerts, call res in advance to find out if there are even any F seats available, there probably won't be. AS transcons are heavily booked in advance with full-fare F psgrs or in U class at the 72 hour mark by AS Gold elites, if the rare U seat remains. So it may be moot. I may be wrong but I believe that using your ecert under 48 or 24 hours prior to dept, may only be done at the MIA ticket counter, subject to U class availability only, and you must have that Ecert number with you (print your copy and bring it with you, with the redemption rules too if possible!). Good luck.

On second thought, double check to see if your Ecert is eilgible on award tickets it may very well not be.