So far, so good, D'karr. A couple things I might contribute, based on your notes:
1) If you have to step away from your sculpting to change diapers (urgh...) or whatever, put the unused putty in the freezer. The cold will help keep it from curing any further until you take it out.
2) Conversely, you can speed up the curing process with heat. When I want a part to hurry up and harden, I stick it into a primitive E-Z Bake oven I made for this purpose. It's just a short length of metal duct used in air-conditioning and such, topped off with one of those kind of shallow conical metal lighting fixtures with the clamp that you see in workshops. (The clamp isn't necessary, by the way - take that off.) The light fixture has a 20 watt (I think...) appliance bulb in it. The end result looks a little bit like a shiny metal hut. Put the figure inside, and cook it in there for 20-30 minutes. When it comes out, it should be cured and ready for your next stage. I'll double check when I get home about the wattage. Does my explanation make sense? If not, I'll see if I can get up a photo or two to clarify. Oh, and I recommend putting the whole thing on top of a ceramic tile - it can get pretty hot in there, and I'd hate to be responsible for damage to your kitchen table or something...
Anyway, good stuff. I look forward to seeing the girallon in his full, four-armed glory!