Another dumb question: can I play Skylanders on my flashcard without using portals or figurines?
Nope. They haven't worked out any way to modify a game yet, and with the original game you need the portal and characters to even get in-game. I wouldn't expect this to be worked around either (at least not in the foreseeable future), as it hasn't on the systems that are much easier to work around stuff like this (wii, 360, etc)