Ok as an update I installed Chrome and as long as the video is not 1080p60 and just regular 1080p it works perfect in small or full screen. Safari it will still do the same stutter and drop an enormous amount of frames. Both browsers are running HTML5 player. I also renamed the AppleGraphicsPowerManagement Kext to disable it and I think that is what helped in Chrome so much. Just not sure why Safari is still giving me issues.
EDIT: It seems that disabling the kext has in fact allowed safari to stream 1080p just fine now 🙂