Specifically addressing the quality, that is going to mostly be dependent on your resolution, framerate, and your bitrate. If you're streaming to twitch, the guideline is 6000kbps maximum (although in actual practice it's 8000kbps maximum before issues occur)... if your network can handle that upload speed, then there's not really much reason not to go for it, unless you're not getting transcoding on twitch.
For your resolution, just go to your video tab in settings and change your Output (scaled) resolution to 1280x720.
Other than that, you have minimal rendering and encoding lag, which is good. Something you can do is turn off psychovisual tuning in your recording encoding settings, as this uses GPU resources to assist in the encoding process.
Also, you have Game DVR and Background Recording both on, which means you're going to be constantly using one of your NVENC streams. If this is your intent for shadowplay recordings, then obviously keep doing what you're doing. But if not, then you may want to disable this to possibly reduce the rendering/encoding lag even further.