Anime, of corse
I think if they did make a movie ( I think they should ) It should try to go over alot of runescape, without seeming too much like an infomercial. Like maybe have a few characters interacting while diong a group-quest (just like what Jagex is trying to make) and it should encorperate alot of the runescape skills and locations. And it will have to have alot of the monsters in it. Maybe seeing "the Old Man" in it would add some comedy to the bit ( seeing him teleport in ang give a box to someone in a random situation? ). And overall I think that if the movie is made, the quest should be made for runescape for us to really try to beat. I think it would be a good idea.
The part of player owned houses could be done, maybe like start the movie out in there, like over the life of one adventurer, his life, and then his embarkment with his friends upon a quest. His name would have to be made so it cannot be used by other runescappers if it used in a movie, to stop them from turning into another Zezima. It should have at least 1 mage, warrior, and archer in the group, to show off each of the 3 combat styles, and each of them will use the skills that are used for their combat style( ex. mage=runecrafting, archer= fletching/woodcutting, warrior= maybe smithing ). During the movie thay can also use the other skills, like fm for making a fire for their camp, or thieving to get a key for the quest, stuff like that. They wont have them "level up" or have the fireworks flash above their heads, that would make the film seem more childish.
They wouldent be able to show him following one of the specific runescape gods, that would cause conflict, but they should talk about the god wars and include alot of the past of runescape. That may add a bit more intrest of others into starting to play runescape, and showing them members stuff will also increase the buying of memberships.
The end of the quest would have to give the 3 adventurers rewards, most likely a new combat item for each of their skills. like a new staff for the mage, with specific powers, a new powerful bow for the archer, and a legendary sword for the warrior.
