I just want to clarify somethings for an upcoming quest.

Are the conjurer's image tokens considered figures?

When summoned, are they considered to have "entered a space"? IOW, would they be subject to damage from entering a pit, or entering lava?

In this case, we are going to play the SoN quest "Widespread Panic" and I'm wondering if the Images can be summoned adjacent to rioters, or if they would suffer the damage immediately, causing them to vanish and the conjurer to take the penalty for losing an image.

Summoning, like reinforcing a monster, is not entering a space. Any subsequent movement would be. I'm currently playing as a Conjurer. I have tried to become very familiar with how those tokens work. For the record, Nathan gives a pretty good rule of thumb in this thread. Generally, if the thing that is being placed was already on the map (a hero who is removed and placed, something that gets knocked back, normal movement, etc) it's almost always counting as "entering a space." When something is placed on the map that wasn't already on the map (monster reinforcements, summoning of familiars or image tokens, heroes standing up after being knocked out) that's not entering a space.