I have to disagree that computers slow things down. I am not sure what your programmers are doing wrong, but there are a whole host of tools that help.
While many of us like rolling actual dice, if you roll 18d6 adding all of them up is a pain. A die roller does that for you.
RPtools has everything from a virtual map to an intitiative tracker. Tools like that and google docs allow people to share information and sheets. The online SRDs for things like Pathfinder and 3.5 and bookmarked / text PDFs allow us to find and sort out rules quickly (though I agree that sometimes you just need a physical copy).
Having played a Malconvoker (summoning specialist) with over 9 summons on the board at a time I created a spreadsheet in my free time. I had only to input the AC of what was being hit, and it would give me a damage output. Refresh, and it would run the turn of the next summon. If your 'programmers' can't do something like that, well...
Lastly as much as I hate to be a software fangirl, I love Fantasy Grounds. From a DM perspective it is simply amazing. I could wax poetic about it for quite a while, so I'll leave it at that.
There is a part of me that likes this idea, then there is the part of me that has experienced a flea infestation. Because of the rapidity of their breading and their general insidiousness you become a little paranoid. I can easily see that being a very strong character trait for an eccentric wizard.
Living in a wizarding town "go fetch X component for a flea-bomb" would make a good low level quest, especially for non-casters. Along that line of thinking there might be entire establishments devoted to cleansing a place of fleas, and the fleas are developing an immunity to whatever the exterminators are using.
A vanity form of immortality seems awfully hollow for a cultist. While the 'picture' interpretation of the book is better it seems to relegate the book the land of fluff. What axlerowes proposes turns it into a sort of accidental intelligent magic item that tries to impress its own desires on the reader, and the implications of that are stellar. I can only imagine a posessed reader confronting an older version of the author. "Look at you, you're everything I have strived against!" Certainly a way to test one's convictions.
I like that this is a face swap and not a face copy. I feel like it needs a backstory about its use in a theater that eventually became infamous as the theater of cruelty. Perhaps this item has a twin mask, the tragedy one, which when it is combined has a sort of special effect. There could be a constant struggle in the seedy underground of the theater to try and hold both masks.
I fourth the desire to own one. It's simply so practical I don't feel it needs any real explanation. It's not a 5/5 post that makes you go "Woah... must... use..." but any DM or even a player can come up with a dozen clever uses for it. I especially like that it doesn't have that overwhelming aura of evil so many things have, it just has uses and 'misuses'.
I find this far superior to your Boo! article which seemed cheesy. I have to disagree with you on the point of not informing your players it is a horror game. Bait and switch is illegal for a reason. If the players did not want to play a horror game, then they have no choice but to leave or have you entirely change the game. Additionally, if they don't realize it is a horror game they will be far less cooperative in creating the mood because a fair portion of D&D is often in the out of game experience.
One idea shared with me was to actually give a picture of the gem to the player. If it's a semi-precious stone you most likely have one or can buy a small bag of them for a couple dollars. Gems are shiny. Really shiny. It's something you don't appreciate when the DM says "you have a 300 GP ruby" until you are looking at a $300 ruby. Beyond rubies, what does an adventurine look like? There are thousands of valuble stones you can use to add flavor.