You can apply for a new US passport or passport renewal and a US passport card at the same time. This is a convenient option for frequent travelers to have both a valid passport for air travel and a passport card for travel to these destinations by land or sea.
As for when you should use a Seal... use Master Seals on non-promoted classes at level 10 to upgrade them, and Second Seals on non-promoted classes at 10 to switch them over to another class tree (mostly worthless, though switching characters that have access to Mercenary, such as the Avatar, over to it ASAP is generally a good idea), or to switch a promoted class into another promoted class at level 15.
1 You can Prestige and get new emblem after level 50. 2  These emblems signifies how far you have reached, these are given after enough XP is gained. 3  You can gain Call of Duty: Advanced Warfare Prestige 15 times. 4  After 15 regular emblems and then you can reach Prestige Master!