Damn.. Hmm is the card using boost or are you using anything like Rivatuner/MSI Afterburner or similar? If so try disabling it or even down clocking the card a little. I'm off to bed so will check back in the morning. Good luck!
Your sensor log looks fine. Make sure your running the latest chipset drivers and remember my suggestion above to try downclocking your gpu simply as a test. As for removing the Realtek driver won't that remove your audio all together? You could try it I guess.
Yes although I'm not exactly sure what 103 relates to.. Maybe megahertz? So you have basically taken 103MHz off the speed. You could always use GPU-Z to check although you'll have to make sure you know what the card is usually set at.
So far iv done a few tests on games (Skyrim, fallout 1/2/3/NV, Men of war assault squad 1/2, metal gear solid 3 and 5) but so far it still happens on some multiplayer games like insurgency, csgo, Ark and War thunder. Although some multiplayer games like mount blade and source games work.