Since a lot of people won't be willing to go through 10 pages of forum posts, I've collected various information about Euphoria below in this post.
About the content of Euphoria:
As for the legality question, I included it because we're not familiar with all the (changing) laws of the European nations. We have a fair idea of where the US law stands, but it becomes more difficult to keep track of many international porn laws.
(For what it's worth, I have played the game to look at the content. As much as it made me want to vomit on several occasions, I was very impressed with the fact that it was able to do that. I do feel the game has great merit as a psychological horror similar to SAW. That's my personal opinion. Those I've spoken to about the game imagine it would sell on shock factor, since if released, it would be the most extreme eroge ever released in English to date.)
Also a few movies related to Euphoria (such as the game OP) can be found at http://entacom.org/clockup/product/euphoria/download.html
About content options in Euphoria:
These:
They work quite interesting way: scat scenes are displayed as is, but with alternate CG that does not explicitly show feces. In guro scenes it shows red screen instead of CG. Text is same.
(Note that there are separate options to toggle scat and guro)
About the script size for Euphoria: