I think the teeth on your crankset look fine. They look nearly new. I'd just ride it until it gave me problems (which may never happen!). A good degreasing or even a flush of those shifters with WD-40 or Tri flow or some such, while shifting back and forth, should get those shifters working well. Lots of info out there about that. Basically, what happens is the factory grease gets all old and gummed up and won't let the pawls return to engage the next tooth in the mechanism. Get that old grease out out of there and some fresh lube in and all will be well. Nice looking bike!