3. new star fields
Didn't the Director's Cut already do this, or are you going with something different?
2. computer screens will get make-over; may consider altering consoles in some way to have more viewscreens and less switches.
I do believe the Nostromo was meant to be a low-tech ship. Adding screens would seem out of place especially considering the mother chat room only has one interactive screen inside it.
3. bouncing helmet in background will be stabilized/static.
Aww. Why? If your going to do that, you might as well remove the banging chair, flapping paper and the bird drinking deco. I myself think that movement in what looks like an abandoned ship makes it more eerie than a ship that's perfectly still.
4. smoke will be deleted when Nostromo detaches from docking arm
Aww, but Scott said he liked that effect, even admitting it makes no sense.
3. may slow down Kane's POV of the face-hugger so we can better see what is happening.
Doesn't that defeat the whole purpose of the shot? Sure, it's hard to spot what's going on, but there is merit to it. "Oh, god. What just happened?" can be a lot more effective. The more you see the Alien doing it's thing, the more comfortable one will be with it.
4. early plotpoint had Ripley being Dallas' lover; if possible, I will be "adding" Ripley laying beside Dallas when Ash calls him in the shuttle (this will set up the cocoon scene later if used)
NO! Don't do that! Ripley is meant to be a very independent character who is supposed to be in conflict with Dallas, not be his bed mate. And it's totally out of place considering that these two argue with each other over orders and command responsibilities. Leave that 'lover' stuff in Alien3 where it belongs (And if you ever get a chance to do ALIEN3, delete the lover stuff).
10. will do some slight editing to the "Dallas in the airshaft" sequence: the camera will close in on him as he descends the ladder, so when he turns the light towards us it will cut to the Alien jump scare (that way we won't see the Alien stuck in the wall).
Well, it's your edit, but I think cutting to the ALIEN the moment Dallas shines his light towards the camera is a bit to quick. Plus, we'd be cutting parts of Lambert's line "No, not that way! Wait! The other way Dallas!"
Those are my thoughts anyway.