How do I export the project back out to its original form once I imported it into the workspace? Or is it safe to just copy the stuff out of my workspace folder?
First of all: you are using version control, right? Please tell me yes.
Eclipse isn't going to "change" your code at all. It'll put two or three files and dirs in the root of your project. That's it. Your code is the same as it was before.
If you move a class to another package in Eclipse (using drag&drop), it will automatically issue the necessary svn move command, and synch up the import statements everywhere. That's a 20 minute job done in 2 seconds.
Eclipse won't change your file/folder structure (unless you tell it to).
In fact, you can have source code somewhere outside of your "workspace" and just point Eclipse to it, there is no requirement for the code to be inside the "workspace".
Eclipse isn't going to "change" your code at all. It'll put two or three files and dirs in the root of your project. That's it. Your code is the same as it was before.