Damn but it's good shit. Anyway, there's been some chatter that Gustavo and his old murdered partner were, "partners". Maybe, Gus's grief and rage at Max's death certainly did seem to go beyond the platonic level. Time will tell whether anything about the nature of their relationship will be revealed or whether it will turn out to be important to the overall story. As of now I don't think so. We should keep in mind that the main purpose of this back story is mechanical. Gus's vendetta against Hector is a big help in allowing the writers to ratchet up the drama by having Walt and Jesse violate most every cardinal rule against pissing off drug lords while providing a credible reason for why they have so far been able to survive doing so. Sometimes open interpretations are allowed not because of any artistic design but because the interpretation simply doesn't matter.
Though it would provide a good reason for how Gus got into the crystal game to begin with. The demographics of meth use, gay men and the rednecks who hate them, is definitely one of the more amusing aspects of human culture.