Is it possible to use this engine to make an action/adevnture game or just an adventure game altogether?
This doesnt help. We dont know your answer unless you tell us what you have in mind. There are many things that it can and cant do.
Him, ok has anyone ever played monkey island 4? You can pick up items and use items with objects in rooms. You can slove puzzles by combining items you find with items in rooms.
Like to pick up objetc a and use it with object b.
To change the game from a killing game into a puzzle sloving universe.
Is that enough?
Not possible. Potentially possible with the basic Q3 engine (since it's open source, unlike the variants used by Raven), but only if you're an extraordinarily proficient coder.
Jedi Academy is an FPS (using that term very loosely) and that's pretty much the way it'll always be.
There are way better open source (and did I mention free?) game engines than Quake 3 for this anyway, all you have to do is attempt to find them.
I don't know how, and I don't know why, but this is totally Sheep's fault.
What about, like chatting with npc's kinda kotor and monkey island? you've got some options to choose from, although I imagin the topic is definatly, coding.
Talking NPCs can be done via ICARUS scripting (basically, playing the voiceover during the cutscene), but conversations like KotOR is definitely outta the question.
Yes, it would require coding, and it'd also require access to the singleplayer source code, which as you know is unavailable.
I don't know how, and I don't know why, but this is totally Sheep's fault.