ID's crafted on the fly
IMHO, that's covered by Disguise and Bluff checks (edit: and Forgery, indeed, for all the fake gear and papers). Mostly Bluff, but Disguise if you need to alter your appearance, accent, or whatever mannerism.
ID's of variable strength.
Hum, good question. I guess I would consider it a Favor, a Military Favor to be precise. What about ...Alternate Identity
: You receive a fully documented alternate identity that lasts for the duration of the adventure. If may be broken with a successful Research check for the given duration and DC (which may be modified as per Table 2.15: Researching (see page 77)
ID Renown Requirement Minimum Downtime Reputation cost
Poor (1d6 hours, DC 15) Military 1 D 5
Average (2d6 hours, DC 20) Military 3 D 15
Documented (1d6 days, DC 25) Military 5 W 25
Flawless (2d6 days, DC 30) Military 7 W 35
Intricate (4d6 days, DC 35) Military 9 M 45