Creative questions.

[Windego]

Hello everyone!

I've begun using a creative world to pre-build ideas and designs before gradually making them in my survival world, to save both time and make it a bit easier to correct mistakes and actually know what I'm doing before I begin.

So here are some questions.
- Is there a command that disables entity spawns, and enables them when entered?
- In world edit, how do I fill in a wall without having to manually fill it in block by block? I know know how to do it for a floor, with the flood fill option.. But not for anything vertical.
- In the events I make something grandiose and I don't want to lose it due to, let's say, a corrupt safe file or to import it into a world that's meant to be a sort of 'design storage facility' thing. How do I copy and export / import builds? Is it possible?
- Can I replace blocks in a specified area without having to delete them first and use the flood fill option?


- Are there people here who would be willing to share their designs with others, including myself, for people to use in their worlds and/or try to replicate if not alter it to their own custom liking? (That is to say, if exporting/importing builds is possible.)
If yes, then please post them below. For safety of avoiding design theft, we could use this post to find the original creator of the build do avoid someone falsely claiming it's theirs.

Thank you all in advance for your help and possible share.