Is it possible to make a mod that register all npc talking? I mean, even general talking, that way I wont loose some non relevant dialogues and so

All relevant conversation is subtitled. Use those.

All speech and subtitles are installed by using machine gibberish. So unless you find a way/program to actually read these files, you will have a bit of a problem.

Please, add "as far as I know" - thank you :) ....