1. Modern
2. Sci-Fi
3. Mountainous Village
4. Medieval Village
5. Floating Islands
6. Large temple
7. Medieval Castle
8. Underwater
I'm quite a big fan of modern/real-world builds.
I only really use Shaders for screenshots, but I prefer Chocapic13's shaders. It looks good, and it's not that frame intensive if you use the Lite version.
Spawnable mobs are not even necessary for creative. They obviously cannot be used as a building material, and they can very easily be used to lag out a plot the plots adjacent. I personally see no reason for them.
As Tasses said, MVP+ still can cause lag machines. While I do support using redstone to add details and unique features to builds, the power can easily be abused.
Looking forward to seeing what it will look like, they are all good ideas. Personally, I like a cave civilization most, but the polls state differently.