I started up a Moebooru-style Booru that I'm hosting from my Linux machine, and I wanted to have it's rules and guidelines be nearly the same. For legal reasons, I won't post the link to my Booru, but I do have to ask, is E621's format copyrighted? I've already adopted the Takedown Policy, Do Not Post, and rules page from the Wiki.

If I am infringing on anything legal, then I will be more than happy to remove them and create my own.

I'm not a lawyer, nor do I work for e621, but I do not see a problem basing your rules/policies on what e621 does. However doing a full copy/paste, it is best to ask permission because people usually pay lawyers to write that stuff, or at least go over it and give advice.
And From what I remember, legal text falls under the same copyright that novels and books fall under, so there is also that.

I'm pretty sure the format isn't copyrighted, at least to e621's possession. The format they use is based from, actually not too sure of the original name, but I'm pretty sure it's simply called Danbooru, but basically, that's the same as Bulbapedia not owning the Wikia format, Wikipedia owns it, I think. However, since e621's format is largely changed from the original Danbooru format, it's likely to hold some form of copyrights unless the original Danbooru conditions of use state that you can't do that.

I'm pretty sure e621 had a footing with some sort of Danbooru link and information but that seems gone now. I can't find the terms of use anywhere but Danbooru's source code is publicly available here https://github.com/r888888888/danbooru and it could be safer to use this instead of e621's

A bit unrelated, but in the early days of our Left 4 Dead 2 server, the writing style of the Code of Conduct of the associated group was heavily inspired by that of e621, and my fellow admins liked it too.
We've altered and removed/replaced some of it, but it's still quite similar.

Okay, then keeping in mind what everybody mentioned, would it be a bad idea to have an admin look it over and give a little feedback so than later down the line I don't get in trouble? _{Also, sorry for the wall of text... lol}

Just PM the site to an admin.

Considering that booru sites are extremely common. I don't think that's an issue.

Neitsuke said:
that's the same as Bulbapedia not owning the Wikia format, Wikipedia owns it, I think.

Wikia and Wikipedia/Wikimedia are two unrelated companies actually.