Hello--congrats on your first hatch. I don't know about the gray rings--can you provide a picture? That would help a lot. Are they on the shell? Are they cracks, or something else? Do they surround the shell, or just circles on it? Sorry I can't help more--but again, a picture would probably go a long way--
As for pipping in the small end, this is usually a problem for the duckling. It is not unusual for a duck to take 24 hours from pipping to making further progress, but my guess is that you will probably have to help this one out. Is there some reason it pipped in the wrong end? In my first hatch, I had one do that, and I realized later it's because I had it sitting in the turner the wrong way up--first timer's mistake--and I had to help it hatch.
If you decide to help, do a search on the forums for "help with hatching" or such, because there is a TON of good information, way more than I could give you in a single response.
Finally, when hatching I generally open the incubator once a day. At that time, I take out all ducklings that are dry or mostly dry, and place them in the brooder. Then I close it up and don't open it again until the next day. It's important to maintain humidity in the incubator during the hatch, and every time you open it the humidity drops and takes a long time to recover. Some people don't open at all until the hatch is completely done.
Have fun!!