The MSQ isn't tied to the deep desert AFAIK. There is no full loot drop outside of a voted on rule change, which I have to imagine will change -very- quickly if people are using it to grief and the majority of players get angry. They did mention the landsgrad thing will change week to week in terms of what you do to get points, so I have to imagine they will mix up voting options as needed as well.
In terms of longevity, hard to say. A lot of these games attract a PVE audience and a PVP audience, but it is extremely hard to make both happy. PVE usually expects regular updates and looking at their DLC slate, even though they mentioned there would be story updates outside of the DLC, there could be a risk of content droughts. Once Human made the mistake of thinking their playerbase would be PVP mostly like in China, but the west usually gravitates towards PVE more, so they got caught with inadequate PVE content.
PVP make their own content, but once you get hackers and exploits in a game, that can kill your audience. The combined arms fighting might be cool, although it sounds like at launch it will mostly be air and infantry (no tanks until later)
