I'm not Jersey, but I might be able to shed some light on the defensive question above.
As for never seeing deep outs or comebacks, it is something that you will see on a rollout more often than a dropback. The ball is in the air too long with the target at a point that is in front of a defender (meaning the defender won't have to turn his hips and run, which means quicker reaction time and a more dangerous pass )when you are throwing from the pocket.
As far as the field corner alignment... it depends on what coverage they are in. If it's man coverage, then yes his job is to align inside and force the receiver to the outside. The reason isn't as much about protecting against a deep out. It does help on slants but an inside alignment gives leverage to force the receiver to the outside and over the top where there is less field (using the sideline as a defender) and also because it forces a throw to the outside (long throw) and where the safety help often is.
If it's zone coverage (in this case Cover 3), then the field corner is aligning at a spot relative to the hash marks. Different teams prefer different alignments, but a good example would be for the field corner to align two or three yards outside the hash with his hips open to the sideline. This, again, is less about specific route protection, but more about creating an advantageous situation where the player can defend his area and the routes he is likely to see the most.