Having spent far too much time in 3.5 I will mention that there are ways of tricking-out baddies without actually giving them items. There could be a misguided Vow of Poverty druid, a cleric or warlock who buffs him/herself a great deal at the start of the day, and my personal favorite Incarnum characters. In fact, there is no reason for an obscenely wealthy noble to not Permenancy a number of buffs on himself instead of walking around with magic items that totally clash with his outfit. None of the aforementioned will drop any magic items when they die either so you can tailor their power without worrying about the characters becoming inflated by magic. If you really want to get your players acting smart give them a bunch of one-use potions or limited-use wands. After all, what average thug can invest in a +4 belt of whatever for the one or two battles he'll have in a year? The players will have to act fast and smart because a prolonged battle will mean less booty when they win.
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.