If idea number 4 is possible, maybe a similar reconstruction can be done for the unrated version of Live Free or Die Hard. I have the Blu-ray (theatrical cut) and the Unrated DVD (I don't even think there's an HD version available for the unrated cut).
Sadly, I only have the DVD for Prince of Darkness. I only know of 720p versions floating around...haven't seen any 1080i or 1080p versions. Considering it's a Universal property, I could see Universal botching it like they usually do with their catalog Blu-ray releases (there are some exceptions, though).
I'd be all for the uncut version of Scream if it's possible, along with the uncensored audio for Day of the Dead. I have this on Blu-ray as well, and it is definitely the best available version, but it still has its faults (a heavy case of DNR for starters). It's a shame that Germany didn't get a truly uncut version on Blu-ray (instead labeling the R-rated cut as "uncut").
There's some potential in these ideas, that's for sure...