For the no-draw-til-stalemate-line bit: I personally like this idea a lot, but it's impossible to implement. The stalemate line needs to be diplomatic and tactical in nature, which can only come about by 1vx stalemates (where x is the total of other players playing, of course).
That is, take the problematic 2v2 situation Alderian described. If one of the four powers remaining cannot stab its ally without being destroyed by the other three, and this situation applies for all four players, then the game has reached a diplomatic stalemate line. Defeat is inevitable if any of the alliances are broken; the two players are effectively playing as one. It is basically like a 1v1 stalemate, so you would think in theory that the idea could be implemented.
In practice, though, there is no way for anyone in some 2v2 scenarios to know with certainty what will happen if they stab. Every player can say in an EoG "Well, if x did y, I would have done z to throw the game to a and b," sure, but in the middle of the game we can only assume and extrapolate from assumptions. This is too subjective an area for someone to lay down a hard-and-fast objective rule (which is why the players decide when to draw, and mods only force a draw when there is objectively no progress to be made -- and even THEN there is enough room for subjectivity that forced draws are very rarely seen).
So while the no-draw-til-stalemate-line idea is sound, and something I follow (unless I'm on the losing end, in which case I'm trying to be devious and use smoke and mirrors to delay the inevitable :P) to the best of my ability... for something as objectively measured as a competitive, points-based league system, it simply cannot work.