5. Do The Back Story Justice
As we've seen in comic-based movies, the origin story can be a bit of a bastardized hybrid and still work. Dig around the different comics and cartoons and a pretty solid back story can be pieced together. The original, pre-Filmation mini-comics explained that Eternians were dealing with the aftermath of the "Great Wars". The wars left behind some advanced technology and weaponry (explains things like Wind Raiders in a land where people still use swords and maces as primary weapons). This is also where we first see the story of the two halves of the Power Sword. One half is possessed by He-Man, the other by Skeletor. Bringing the two halves together creates the true Power Sword. The 2002 cartoon and the D.C. comic provided different but cool back stories for Skeletor and King Randor. Some fans abhor origin stories, but MOTU really offers the chance to provide some great back stories for the primary characters. Starting X-Men with the great Magneto origin worked. Starting MOTU off with the Randor and Skeletor/Keldor story would be a great way to kick off the new franchise.
The right decision: Showing Skeletor go from fleshy warrior to bony villain.
The wrong decision: A hokey, narrated origin montage.