try doing some research before spouting things like "it's impossible" NOTHING is impossible, especially with minecraft. Along with a new experience with the Kinect. Not only is it "not a coding thing" to make it cross platform, they've already announced it WOULD BE cross platform this winter. Nevermind, I just remembered that the PC version is written in Java, and that the xbox version is written in a variant of C I belive, so cross-platform multiplayer is virtually impossible.
Doing so is a technological feat I was surprised that the Pocket Edition could do so with other phones. I HIGHLY doubt that multiplayer servers will be cross-platform. Honestly if you cant deal with such possibilities, why even bother making a server, all who cant deal with it don't trip and eat some chicken strips If you are really going to worry about people spamming your chat about nonsense don't even worry about that, i think its a lot better than what those spam bots come up with, it's nothing a good plugin cant fix in an instant. Stop fixing your mind thinking that other people that are used to a different style of gaming might end up choosing bad decisions, you will come across times where you will have to accept the fact that things will happen and you will have to deal with them accordingly. If you are worrying your bum off thinking that the immature section of xbox live are going to greif the hell out of your servers, then at least consider the fact that they will only be able to grief using vanilla methods, but even if there weren't any xbox live players you should always have a reliable anti griefing plugin for ex:Hawkeye,BigBrother,or LogBlock. Alright i'm just going to throw this out there.