Your upload is quite limited so you're going to have to stream downscaled, You need at least 2000 -stable- for decent 720 in my opinion, personally I'd probably recommend 2.0x downscale at the very least, 96k or less for audio. Try the FPS range and see what works and what looks good. You can experiment with these values by outputting to file only as well if you wish.
If you have ping issues you need to use "minimize network impact" in broadcast settings.
