Ok, so I had a long half- day talk with Kharay on Steam.......
Result- it still flickers, and we've absolutely no idea what can go wrong, since we are doing almost identical things, and he can stream fine- and I cant.
I am extremely grateful to Kharay for devoting his time to my problem, and I am sure there are many other people who received advices from Kharay- even though I still cant stream in full screen, I at least know for sure that the problem is not in my hardware, or the settings, of either game or OBS, so hopefully I would be able to work out exactly why the stream is not perfect- for now, I will continue streaming Monitor capture, and again, thanks to Kharay, I found out plenty of interesting facts about how broadcasting software works.
Again, thanks to Kharay- and, in fact everyone else on these forums for support- My actual other Stream of Saints Row 4 started to work properly, even though I didnt expect it to, so me and Kharay did not fail- we just succeded at finding many ways that would not work =P
Thanks again,
I will probably keep posting here from time to time on other threads, where I can.