I have the same processor as you too, am playing at 1080p and the game is installed on an SSD and is played on Windows 7. I had to jump AA down to FXAA (post-processing, not real AA), disable bloom, disable ambient occlusion, and notch down a few other settings, vaguely recall shadow and lighting, but haven't played in two days so I'm not sure. Oddly, switching from fullscreen to borderless windowed (I have two monitors) improved performance, when in all cases the opposite should happen.
Every couple seconds the game has a small 'hiccup' for a few frames which is visibly noticeable and jarring. It makes smooth gameplay virtually impossible. I find it so unbearable I am not willing to play the game until its fixed. Also, I've experienced a lot of the position glitching issues you mentioned. They crop up most when climbing/descending. At one point, I was climbing on a ledge that had a ledge 'undercarriage' if you will, and the character only made it halfway up, got stuck in the undercarriage, and slowly slipped down into the pile of enemies I was running from. Not fond memories of the original Counter Strike clipping issues with vehicles on servers came to mind.