yes all are possible, the only limitation of what is possible is the extent of programming knowledge by the programmer.
Just from the questions ur asking, im guessing ur biting off a lot more than u can chew. if i know the answer i wont mind sharing but ur asking some very vague questions. i think of it like ur walking into a chemistry class announcing you are the lead researcher on a cancer cure project and then asking people if making a cure for cancer is possible and if so then how? xD
...nonetheless... good luck
Thanks for the friendly answer, certainly didn't expect that.
I'm famliar with programming/scripting in many other games but I'm not 100% sure when it comes to IV.
I understand it being hard to answer, It does seem vague looking back at it, Netherless It might be better if I had help,
Thanks again and Cheers!
yeah no hard feelings, i was just being funny, im no expert on gta or even programming but if i know something i wont mind helping, i am sincere about that
cutscenes are limited to available speech and animations, anything that gta doesnt do u would need to figure out how to make an import speech and animations that would work in gta. Then play them at appropriate times via script. Possible yes, do i know how, no.
for multiplayer option, i assume u will need skills in reversing as i havent seen anyone mess with this functionality.
for making script work together... u make the author's conscience of each other's scripts and u write to work together... or u edit the source code urself when available
there is a c++ hoook u can use if u prefer c++ or there is .net using c#.