Jagex did say BETA would come first to RS P2P members only, it was in a news post not so long ago. Yes. They have done it with all the RS versions to date so it makes sense that they would continue in that vein.
Mage defense is almost entirely based off your mage level. Someone with 99 defence and 90 magic will be hit more my mage attacks then someone with 99 magic and 1 defence.
Maybe not so near-sighted. While there is currently a lot of anger, I believe, and others have made the point as well, that the rioters don't have the stomach yet for prolonged strike. They can riot for a few days but I doubt it will have much affect.