Re: can I has all your data?
A few months back I kept getting pestered by friends to install the messenger app, so I did and it was a buggy POS that killed my battery. I uninstalled it and when I got blocked from sending messages through the app I switched to using the website m.facebook.com and uninstalled the app. I still use the mobile site around the same amount of times I used to use the app, but one thing I've noticed on Android is my battery is at least 20% healthier per day for it and that is on an S4.
Facebook are slowly, but surely trying to build their own walled garden, which is fair enough they are out there to make money, but the main reasons I'm on there - following friends / bands / a few pages can all be done on twitter and organised much better using tweetdeck. If they remove the messaging feature from m.facebook.com then I think they'll lose a few customers, but they won't be bothered by it as the numbers will just be a drop in the ocean.