I have an idea for a world that is separate where you have plots, 16x16 or 32x32, that you can build a house in to save stuff there and that you can reset the outside world without loosing your stuff. You can have the shops and some more build options like bigger plots for estates for moderators/admins that show off there building skills. You can also do more with this world that would be easier than building it in a normal world. This is my idea hope you can use it.

Meh, I'll disagree with this also. The world we are currently in right now on the server is enough for the daily Minecrafters/Noobs that get on everyday. Getting another world will only make it more mind boggling.

...build a house in to save stuff there and that you can reset the outside world without loosing your stuff. You can have the shops and some more build options like bigger plots...

If it's just about having larger build areas, people can build in the Wilderness and even set up shops there as well. It may not be officially protected, but /grief does the job if someone messes it up. Plus, you'll get way more than just a 32x32 plot, without upping your plot count. And you're free to choose your own strategic location.

On the other hand. What about the hypothetical scenario when Noobstown needs to update to a new version (V6) and the whole world has to be reset? Would it be an interesting idea to simultaneously have another world (to slowly transition into), perhaps with jungle biomes and some of the other newer features, and save that world for the next version?

Well, As you may or may not know. Noobstown IS in V5. Meaning we have lost all of our stuff before. And yes it's frusturating. But you know what? You build a bridge and get over it.