Our gaming group has been playing MOM pretty much since 2nd edition came out, and have gradually evolved a series of minor tweaks and additions that we think improve the game. So I wanted to share them in case they help anyone else.

https://1drv.ms/b/s!AvT-KVJtCzMmgeUHYHlbgcEsUJuKbA

I'd love to hear any feedback. I should also mention that the new rules for Akachi Onyele and (obviously) Tommy Muldoon are relatively untested; everything else has been playtested quite a bit.

"But why did you change..."

Barricades: Unless all of the monsters have Brawn 2 or at most 3, it's almost not worth placing a barricade. This justifies it, so it's never a "wasted" action unless you place it in the wrong spot.

Insanity: These fixes don't change the difficulty, but do keep things more fun. The first rule prevents someone from drawing an impossible Insane card late in the game; nothing's worse than getting Obsessive or Pyromania on the last turn. This way, you can at least try to plan ahead a bit, which is also more realistic (insanity isn't a sudden snap, but an exacerbation of existing issues). The second one avoids the game ending anticlimactically. We really hated hearing, "Well, the game just ended because this card said so." This way, the insanity is still likely to make you lose, but you get to play out the slow decline into failure.

Signature Gear: Personal preference; this makes them feel like character abilities, not a starting-game bonus. It's zero-sum -- "cannot trade" balances "cannot drop/lose," basically.

Scaling: The game does a great job at scaling monster strength, but the size of the map doesn't scale! Some scenarios are nearly impossible with two or three investigators. This just puts them on a fair playing field, and also makes Wounded suck a little more.

Akachi: My gods does her ability suck. Boring and useless. This makes it just useful enough.

Amanda: Not 100% necessary, but we noticed that the odds of her being the one to get a puzzle were slim, and this (very minor) ability made her feel more useful and really fit her "Student" role.

Bob: Some maps have zero Person tokens at times! And even the most populated map spreads them far, far apart. So while Bob's ability is fine, he needs another way to justify its use.

Rita: Please. No one leaves Rita out of a party by choice; she's too good. This fix at least gives you a reason to consider playing without her.

Tommy: Starts with a top-tier gun and can reroll anything once? Too good. This is a minor nerf, but one that makes perfect sense; he's still amazing.

Wendy: Stunned and Restrained come up so rarely that it's easy to forget she even has a special ability. This is a very minor tweak, but one that at least makes her feel more potent.

I like the changes. Funny thing, I have already photoshopped and printed out new text for the insanity cards that caused anti-climactic ends to the game, the result being almost exactly what your group came up with. We play barricades the same way too, and have also used that fix on Amanda that you propose.

The Know Your Demons rule look pretty fun, will try that though I suspect some insanities will never see play that way.
I'm curious about the Scaling for Small Groups. About half my games have been with just 2 players, and we have lost most of those games. Playing 4 players is a lot easier. Having a look at the submitted statistics, we can see that 2 player games have by far the worst win rate, going up a bit at 3 players, and leveling out at 4-5 players.

I have also failed to submit many of my failed 2-player games, but I think i have submitted all my 4-5 player games, and all successes due to simple psychology. Since that has happened to me, there is also reasons to suspect others might have done the same, meaning the statistics are skewed in the favor of success (so the imbalance might be even worse than what is reported).

Will likely try all of these out, though I'm not sure about the Know Your Demons rule...

In my experience, Know Your Demons doesn't knock out any specific Insane cards, because everyone has a different definition of what's "un-fun." Some players really hate having their actions restricted, others hate being traitors, and others are tactical and hate the ones that are just hard to complete. I can't say I've seen any Insane cards universally rejected; they all still end up in play at some point, but in the hands of people who don't mind playing them. (Heck, I've had players discard Suspicious because, despite being the "best" Insane card, they thought it was boring.)

The 2- and 3-player scaling problem is definitely an issue. It isn't just you seeing this discrepancy. We tried one scenario with two players three times and failed, then retried with five players and won without a single Wounded or Insane person.

I hope these help you, whichever ones you end up using!