Telehax, I've never seen it written that you can apply multiple sources of poison to a weapon - the exception would be the alchemical capsule retainer, which was designed to hold crappy alchemical items instead of poisons, and was most likely an oversight. So it's a DM's call in my opinion, but I don't think it's RAI that multiple poisons on the same weapon will stack.
Even if your DM rules against it, you can still probably double up if you have a poisonous bite attack and a poison-giving spell affecting your bite, or a poisoned spell-storing weapon along with a poisoned touch spell or something.
Ed-Zero, I'll start working on adding in most of the stuff you mentioned, lots of great finds there! Those epic poisons are ridiculously terrible...I love the example:
For example, an assassin crafting lyzeum begins by spending 110,000 gp in raw materials. On his first Craft (poisonmaking) skill check, he rolls a 71. Multiplying this result by the DC of 59 results in a total of 4,189, which means that he has created 41,890 gp worth of poison -- roughly 1/8 of a dose. Assuming similar success, the task will be complete in another seven weeks or so.
Oh goodie, only 7 more weeks before I can finish making my DC 25 injury poison that deals 1d6 Dex damage! And I only spent an epic feat and 390,000g to make it too!
I'll upgrade both the Black Dog and the Factotum a level as well. I had been under the mistaken impression that the Black Dog's poison-related powers only affected the poisons that he made with the Create Poison ability. I'm not sure about Cunning Insight working with poison damage as opposed to weapon damage, but it's probably do-able. It might also work the same way as point blank shot and ability damage, where the it doesn't add to damage since ability damage isn't "true" damage.
