And no, ticket solution won't be better because I'm pretty sure that internal bug tracker of Larian filled with bunch of these and they don't need another headache (which most likely again will be filled with duplicates or similar issues).
That's not even remotely true. An internal bug tracker will only reveal a very, very, very small portion of the bugs in a game. This is why game testing is ESSENTIAL for game development, for everyone. Saying Larian shouldn't bother testing their game because it would be "too hard" for them is absurd. They are game developers, game testing is part of game development, as is improving and fixing the game based on feedback from that testing.
It's also silly to claim that all of the issues will inevitably be fixed when the game is finished. Obviously, every bug is the result of something that's not finished... because it's only "finished" when it's not bugged.
And it's also inevitable that duplicate suggestions/bug reports would be filed NO MATTER the medium. A ticket system would organize and sort that information. With a forum, everything is lumped in one place--actually, more than one place, as with no clear venue for feedback, people will be giving alpha feedback on a half-dozen different forums.
The simple fact of the matter is that a ticket system has nothing but advantages over the current "nothing" system. And arguing against it because you're afraid that taking the time to establish an efficient method of delivering feedback in order to better develop the game might give someone a headache is, frankly, offensive.