I'm getting the impression that the molds created using the MoldGel product is not resusable. Also seems as though it must be poured into rather quickly (2 hours?). True?

Well almost all true. It depends on where you are. The mold is a temporary mold and most people will only get one pull from the aginate mold. (I've heard of a few people that can get up to 3, but they are quite experienced with the material).

The life of the mold can be prolonged by wrapping with wet paper towels and placing in the fridge. But really it should be used with in the same day. The alginate is mostly water, once the water evaporates you get shrinking and distortion. If you live in say Phoenix, Arizona, USA then you're not going to have that much time to cast (a couple hours, unless you do the fridge trick). If you live in say - Seattle, WA, USA, then your mold isn't going to 'dry out' as fast.

There are many options for a permenant mold though, even some skin safe silicones (polytek, smooth-on, and artmolds have them).

Good luck.
Niki