Well, first off, if every Alchemical reaction has it's equivalent in death over on our side of the gate, then what about really little transmutations? Does a broken toaster take, like, a sick lepperous deformed baby? Does HT take a nuke? Or are all lives equal? (That'd be irony there, if so, I figure. Proof that Touka Koukan really is a figment.)
And how does the Stone affect this? If it eliminates Touka Koukan, does that mean that it also eliminates the rebound of a person on the other side of the gate dying? And if for every transmutation on their side, someone on our side dies, wouldn't they be more overpopulated? Unless, perhaps, the sheer amount of times that alchemy is involved in killing people actually balances it out, which could be entirely possible, given the mass destruction used for things like the creation of the Stone.
And they showed the Atomic Weapon there briefly, but also stated that it was occurring in 1916. And Hohenheim said something about the future. So, perhaps, the Gate has no concept of time? Does time span equally on both sides, and inside the Gate there is no time, so viewing through it allows all to be seen? That might make sense, because Ed sure saw a lot of different history of our world when he saw into the Gate.
Interesting that Ed would choose to cling to the concept of a world that is perfectly balanced and fair, rather than one that can give you great evil, but also great good without requiring an equal ammount of either. Luck of the draw, I suppose. Like Hohenheim said - Touka Koukan doesn't allow for an unselfish, unreciprocated love or kindness. It's perfectly structured and allows only for a neutrality of things - you can only get great good if great evil also happens. While it's predictable, it's also kinda sad too.
Also, one thing I noted, being the rabid Badass!Ed fangirl that I am - even knowing that every transmutation killed some random person on another side of the Gate in another world that he knew nothing about, when Al was in danger, he was ready to use Alchemy. =D Now that's just amusing somehow.
And it would seem a silly thing for them to totally disrupt how we've viewed the Gate and Alchemy up till now (they keep doing that, don't they, though?), then randomly not use it anywhere. If Dante keeps sending people randomly through the Gate, then she may not know the true nature of things, or she might, given what she said to Ed in 49. Either way, though, I figure that 51 will make some definate use of the revelations, just like all the previous episodes have built upon the changes in the show's nature.