Since this is my first fan edit (though I have been editing for twelve years now) I have a deep appreciation for all the hard work of the people involved, even bad films. I'm not interested in completely restructuring the Indy 4. What I want to do is remove the kid friendly elements that were just plain stupid. This includes the prairie dogs, the bouncing refrigerator, swinging in the vines, etc.
So... in answer to your questions:
1. & 2.) The opening sequence will stay intact. It really didn't bother me. While we'll get the classic Paramount logo fading into the prairie dog mound there will be no prairie dog. I think what I've done works really well here.
3.) I haven't decided about the wedding ending, but I didn't much care for it. It will probably be cut.
4.) Both. The source is from the NTSC DVD (sorry... no HD... just too much work to rip and convert from Blu-Ray on a Mac at this time) but I have plug-in for FCP that can convert to PAL.
5.) A very slight amount. I will also be adding grain though to match the previous films.
6.) As of right now I plan on keeping the final audio mix 5.1.