First of all, if someone like Lund wants to make a theory like this they should at least quote to movie accurately. The technique Beatrix uses is the "five point palm exploding heart" technique. Second, why would Tarantino include Pai Mei teaching Beatrix the technique? Because that would very blatantly give away the ending. Thirdly, the play acting has no contribution to whether Bill is still alive or not. Bill obviously wasn't playing possum, because he only showed blood after Beatrix did the technique. Lastly, Elle Driver is likely alive even though she was left blind and squirming in a hodunk trailer with a black mamba; Bill is dead, however, because if he wasn't or if it was unsure, wouldn't the question mark be by his name too?