I'm pretty sure you'd solve #2 if you let users completely block apps from their wall. I block every app-related post I can. I use facebook to see what my friends say, not to see what apps they're using.
/ Or perhaps have an option to "block apps in this category". So if I'm clicking on the x for a game's posting trying to entice me in it could offer me the choice to block that game or to block all games.
/ Or perhaps have an option to "block apps in this category". So if I'm clicking on the x for a game's posting trying to entice me in it could offer me the choice to block that game or to block all games.