I need that lens!
My cheap telephoto lens
Its actually not horribly bad as a telephoto lens considering it wasnt made for a camera. But my camera mounts perfectly to it. I do have to crop the pictures down but all in all its not bad for $50 and Im only using a point and shoot so its not like I would take amazing pictures with it anyway.
The only picture I have taken with it so far. Plan to try and get pictures of the moon, but the damn moon decides to be under me at night now so will have to wait till this weekend when the moon is out during the day.
Oh yeah, there are mounts out there which you can buy that allow you to attach your camera body to a telescope. Pretty sure my local photography shop sells them.
Nice, they're good cameras. I see you've also got a flashgun.
I can't speak for the 55-200 (since I own the 55-300) but I can say that the kit 18-55 lens is a really good lens.
I can say that it has made me want to get 2 more lenses in the future. The F/1.8 35mm for night photography that I seen and maybe one with a little more zoom.
I've had a play with the f/1.8 35mm with my D3200. It's a really nice affordable lens actually. I've got some test shots of it on my Flickr if you're interested here http://www.flickr.com/photos/jasonbrown2013/9489146944/ and here http://www.flickr.com/photos/jasonbrown2013/9489145798/in/photostream/
I was going to buy it, so I went to my local photography shop to have a go, but when I told the sales person that I wanted to do landscapes he recommend the Sigma 10-20 f/4.0-5.6 to me instead (which for landscapes is a better lens). I took some test shots with that - just to give you an idea of how wide 10mm is (even on a crop body), here is a test shot I took with it http://www.flickr.com/photos/jasonbrown2013/9489145602/ and in B&W http://www.flickr.com/photos/jasonbrown2013/9489144284/
So, I think my next lens purchase is definitely going to be the Sigma 10-20 f/4.0-5.6, but I might get the 35mm a bit later down the line. I'm not too sure what I'd do with the 35mm but as you said, it's good for night photography because of the large aperture.
As for a longer lens, I've got the 55-300 and you can zoom in pretty close to things with that. Again, look on my Flickr http://www.flickr.com/photos/jasonbrown2013/sets/72157633401330395/ there's a load of shots I've taken with my 55-300. It's a great lens but I'm not too sure if I'd upgrade from a 55-200, unless you'd be prepared to get rid of the 55-200 perhaps. As you can see, I use it mainly for wildlife photography, airshows and flowers.
There's the 600m Nikkor but it costs an arm and a leg and those long lenses are usually best off on the DX bodies probably. They'd seriously dwarf a D3100 haha!
It's good that you're learning with all the manual modes. Are you also shooting in RAW? If you want to edit, then RAW all the way!