As a big fan of all 3 Evil Dead films, I am excited about your project. I have a few ideas, and some questions:
1. This would probably take a lot of work, but you might want to rotoscope or somehow add blood into the Army of Darkness segment. If it were done right, this could help with continuity and make it somewhat more enjoyable for those who prefer the first two movies.
2. I am unclear about whether or not you're using an HD scan of the first Evil Dead. After all, a review on a Blu-Ray site says that the first one is actually a better transfer than #2.
3. Please, oh please use the S-Mart ending! I like it much more than the other one. (Maybe you could include the other one as a special feature, though..)
4. I'm also using a Mac. (EDIT: Not anymore, but I can still work with QuickTime encoding sometimes.) Disk Utility can make iso files. I don't remember exactly how, but Google probable does. :-)
Thanks for reading my first post, and good luck with this cool project.