It would help if I could see a picture of your bike.

1. "Knarled" teeth on the crankset sprockets may be normal. Find a knarled tooth and check the opposite side of the sprocket. If you find a tooth that looks exactly the same, that's a shifting aid that's designed into the crankset.

2. If your bike has a one piece crank, the bottom bracket cups are pressed into the frame. If that's the case, it's possible to replace them with a pressed in adapter to install a euro-style bottom bracket, but the whole conversion might not be very cost effective.