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.
Two way to level Engineering. If your character is below level 90, visit my Engineering Leveling Guide for players below level 90. This guide is for level 90-110 players. There are currently two ways to level Engineering up to 625. One is with Draenor materials because they are really cheap. The other options is to use the new Legion recipes, but it will cost you a lot more. However, using the new Legion recipes, you get items that are useful and can be sold at the Auction House.