What are the differences between the full uncut + the shorter versions?

Well, I have the 96-minute VHS version, and I've seen a couple of the others. So far as I can tell, the slight discrepancy in times likely has more to do with credits and localization than censorship; specifically, a Spanish-dubbed version on laser-disc that I've seen played an instrumental of the theme song rather than the version with Phoebe Cates singing the lyrics over the credits, and these were slightly different credits too. Being in PAL, the movie was also sped up to 25 frames per second instead of the 23.976 in my VHS tape's native NTSC format, which means in addition to everyone's voice having a bit of a high whine to it, the movie was about 4% shorter (making it about 92-93 minutes if you do the math). It also displayed a different distributor's logo (Studio Canal) at the start.

Apart from that, the 100 minute version? Probably a special edition and/or director's cut. I notice in the publicity photos shown on this movie's page that there's a picture of the happy couple in wedding clothes, and Sarah was quite noticeably wearing a wedding ring at the end when inviting David to feel the baby kicking inside her, but there's no wedding scene on my VHS tape's version. I suspect that scene was filmed, but got cut from the theatrical release.

Speaking of cuts, if what you have is a widescreen version, whether anything's blurred out or not (if it is, that's the censored Asian release), you're getting ripped off; the widescreen version is just the fullscreen version with fake letterboxing, i.e. the hack editors chopped off the top and the bottom to make it 16:9 instead of the original 4:3. This is one of the rare examples of a film in which the full 4:3 ratio is the way the original movie was always meant to be viewed.