FAQ for
Halloween: The Curse of Michael Myers (1995) More at IMDbPro »

There are 3 different versions of the sixth installment of the franchise. Besides the theatrical version there's also an unrated cut of the movie and the producer's cut. Like the Producer's Cut, the Unrated Theatrical Cut was never officially licensed released and only published as a bootleg. Of course, this version does not reinvent the movie, and, except for one rather interesting extension at the end, the lengthened scenes of violence aren't really worth mentioning. For collectors and completists though, this version surely is interesting. A detailed comparison between the theatrical cut and the unrated version can be found here.

A detailed comparison between the theatrical cut and the producer's cut can be found here.

To a large extent, yes at least in the Part 4-6 continuity whereas the following sequel Halloween H20 retcons these movies out of continuity. Michael Myers is the victim of a supernatural curse placed on him when he is a child that drives him to kill in order to provide sacrifices for a demon called Thorn. This is why he does what he does and why he's so strong and unkillable. Dr Wynn (a Celtic term for a pagan priest/disciple) was originally the head of a cult that cursed Michael which is clearly explained in the Producer's Cut of the film. However in the Theatrical Cut, he and the Smith's Grove staff became scientists who are posing as a real Thorn cult to exploit Michael's evil they believed can be within his DNA.

There are a variety of different interpretations but this is the last film in the Halloween 4-5-6 continuity. Halloween 7-8 are an alternate storyline where no one has heard of Michael Myers since 1978. In the ending for Halloween 6 Myers' fate was left ambiguous in case the makers wanted to make another sequel in the 4-5-6 reality. But as there are no more films continuing this narrative thread it is widely accepted that the screaming heard at the end is Dr Loomis presumably killing Michael for good off screen.

Even the theatrical version was cut in violent scenes before release in the US, to warrant an R-rating. This version is the only officially released version in the world. The unrated version is only available as a bootleg in the US. The US-TV-Cut on the other hand is sort of a mixed version. It is based on the already cut theatrical version, but then the violent and the sex-scenes were additionally censored. Furthermore, there are some scenes here, that are found in the Producer's Cut, too - they were added to increase the runtime for the broadcast to be able to show more advertising; a typical approach in the US. A detailed comparison between both versions with pictures can be found here.