Update:
1) When you "PREVIEW" I suspect that's not well threaded so thus no noticeable difference. However, not sure if there are any settings in the program, possibly related to GPU acceleration that can help.
2) When you are "rendering out" which I assume means after preview and thus rendering content you actually want as close to 100% as possible so your CPU is fully used.
People getting 30% only means 70% of their CPU is not being used. It may be happening but that simply means the program and settings chosen means at that point in time the CPU code is not well threaded (or possibly at that time it's using the GPU encode/decode hardware).
CPU usage also varies depending on what's going on at the moment, settings chosen, is anything GPU optimized and if so is video editing program properly setup to use your GPU?
(93% usage BTW means you are getting better performance at the point in time than you would on the FX-6300 since at stock settings it can process roughly 40% more data)
3) SSD:
There are times when an SSD can help. Not sure of setup details. Probably looking in settings and assigning any work folders to the SSD and having the video itself in the SSD as well.
4) Webcam:
I'm not sure what the problem is there, plus you haven't really spelled out the details well. For example, are you comparing the game by itself then comparing while also recording VIDEO? Are you streaming? etc..
I doubt the webcam results are incorrect though there may be a better PROGRAM to use such as Shadowplay or OBS (OBS set to use the NVENC decoder) depending on what exactly you're doing.