About the THEMIS pix to aid MER landing site selection
I don't know how extensive the effort has been, or how much of the product has been turned over, but at the presentation I attended, the presenter specifically mentioned that MER landing sites were by far taking priority over other THEMIS targets.
They also showed a context pic of one potential landing site (please forgive me for not remembering which one!) with 50 -100 swaths overlayed that represented the current THEMIS coverage of the area. Probably, this is the same as you mention from the sites selection workshop.
I would guess MOC will be the tool of choice owing to the greater resolution.