To be fair you seems to have a very "slow" mind ....
"Railjack missions (you need to know exactly what u are doing or you will fail)" What? ... you just go .... pew pew the S#&$s and done :S . Now after the neft its almost imposible to fail .
"Fish Rare fish..." takes less than 10 minutes .
"Nightwave 3 - The Clue Search/Puzzle game. Even with watching a video guide took me like 10 hours to solve the puzzle" .... takes an hour at most without using any guide .... with a guide you have to be very "special" to not being able to do it in minutes .
"Hydralist? Never seen one, Never fighted one, Dunno how to fight one." You have more then 1 year here :facepalm : .... Learn how to do , same as in any other game with bosses .
"still dunno how it works even after hours of video watching and wiki reading. " Another thing of your "special" mind .... Kill kuva baby with the weapon you want , kill thralls and the lich in the nodes their control to farm murmurs .... kill the lich with the correct parazon mods and profit ..... its so hard that you need a guide ?