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.
If you've played Awakening heart seals are basically second seals except they don't reset your level. Later when you upgrade your rod shop you can buy as many as you want. You can use those whenever you decide. Master seals work they same way. Its best to you those when a characters hits max level (lv 20). That way they gain as many stats as they can, also classes gain skills as level 5 and 15.