After having my initial question about sniper zoom sensitivity answered in this thread: http://teamfortress.tv/thread/24546/freezing-and-timing-out i am experiencing freezing, stuttering, sound-looping and after some time i time out in both TF2 and CS:GO, leading me to believe this is a source-engine related problem. I would really appreciate some help in this matter, as if it is resolved, it could help many other players with similar issues.
I have tried reinstalling steam, reinstalling tf2, running tf2 without scripts / mods, unblocking all possible tf2 ports on my router, uninstalling my antivirus and antimalware (in safe mode with internet unplugged ofc) and verifying game cache (on both tf2 and cs:go). I would appreciate some advice on the issue at hand.

EDIT 1:
I am using graphics configs but even when i remove them the problem persists.

My specs are a 5820K @ 4ghz, gtx 970 @ 1455mhz core and 7500mhz mem, 16GB DDR4 ram, x99 ud5, MX100 512GB(the rest are unimportant i suppose).

I have reinstalled both games and steam on separate occasions as well as trying backed up versions.

I am running all my games on an SSD (MX100 512GB) but have tried running tf2 on my WD 2TB Green.

EDIT 2: Made a short clip of the problem:
https://www.youtube.com/watch?v=117F4R9ctE0&feature=youtu.be (note, in the first 2 seconds there is also some freezing and lagging, just not so obvious)

Update 1: I am also getting "CD Authentication error" occasionally. I also get the "game is in insecure mode" error some times.

Thank you,
TeaX