You have a similar computer build to what I use, and my setup works pretty well. Let's try a few things. If you'd like to narrow down exactly what the issue is, test your stream after each step. If you just want to fix your problem, follow the steps below and test afterward.
At a glance, a few things that stand out in your log are a bunch of audio buffering, some encoding lag, and no actual game capture hooking occurs.
- Update to OBS Studio 0.15.2 so we know you're working with the latest stable release.
- If you're using a 64-bit version of Windows, try the 64-bit version of OBS Studio.
- Your audio sample rate is set to 48khz. Was that done intentionally for some reason? If not, try changing it to 44.1khz.
- You have the same audio device mapped twice. Is that intentional? If not, set Desktop Audio Device 2 (Settings > Audio) to Disabled.
- Since you said the game looks choppy on stream, I assume you have successfully captured and streamed gameplay. What game? What's your CPU usage like during gameplay only? How about gameplay and streaming? Check Task Manager, not the CPU usage in OBS Studio.
At this point, you should retest and see if things have improved. If they haven't, post a new log with a streaming attempt or carry on.
- If you are not going to stream/record 1080p video, you should rescale your resolution to 1280x720 in Settings > Video > Output (Scaled) Resolution. If I recall correctly, it's more efficient to rescale there than rescaling in the streaming settings.
- Your CPU should be able to handle Lanczos scaling, but feel free to experiment with the Downscale Filter (Settings > Video > Downscale Filter).
- If 60 FPS isn't critical to you, try 30 FPS (Settings > Video > Common FPS Values).
Some optional stuff that shouldn't be related to your issue, but could be useful to you.
- Verify that your upload speed and Twitch speed can handle streaming. Run the Twitch Bandwidth Test using a Medium Test Duration for your region with a 64k TCP Window Size.
- Set your Twitch server (OBS Studio Settings > Stream > Server) to the one that has the highest quality according to the Twitch Bandwidth Test.
If you're still having issues at this point, definitely post a new log from a streaming session that exhibits this problem.