Wyeast 1272 or Denny Favorite 50 Wyeast 1450 they both work really with Rye flavors. I would tend to avoid looking for a yeast that throws off fruit esters.
Double check your temperature probe. Sounds like low mash temps, I make most of my beers 152 or above, as lower on my system makes for thin crappy beers.
It could be different ingredients in the graham crackers. I'm in Canada, so they might be made by a different company using the same marketing name.. That's just a guess.
I've been reading your huge thread and haven't got to the end, but I hope you've caught your math mistake in the quote above.
If you half the voltage, you quarter the watts. :(
The same thing happened to my batch. Worst Beer EVER!. I don't know what is in the Graham crackers but it sure doesn't play well in beer.
I used Honey made graham crackers.