Most FS bikes need new bushings now and then. Some of these can be expensive to buy replacement parts, and generally they have to be pressed in with a bearing press although you can usually ghetto around it, if you really want. (I would just have a shop replace them.)

I haven't personally heard of anything more serious with Niner, but you can google or just mosey over to MTBR in the Niner forum.

CVA is under the bottom bracket so I guess if you high centered just right on a rock you could conceivably damage it. I think doing that on any bike that doesn't have a BB skidplate would be trouble, it's just that Niner happens to have a linkage down there. A lot of riding areas don't have the right types of rock gardens for that to be a concern, anyway.