No necessarily true, I rode my foils 30+ days last year and they are still just as flexy as when I got them. I think it would take a lot more use to actually notice a difference.
Not sure about the stiffness of the gun, but foils are pretty soft, which is why i got a pair of 186 blends. I got the 08's for $400 shipped off twin tip nation, which is a pretty good deal. I'd go with the blend, they look like they're gonna be super sick.