Those look like good settings, although there's no need to "rescale output" on the OBS Output tab. You have that taken care of on the Video tab with the Output (scaled) resolution.
If you have a 1080p monitor, the base canvas being 1080p is perfect.
If you stream at those settings and your CPU usage goes too high because you're on the "Fast" preset, you might want to knock that down to Faster or Veryfast and see how it performs.
If your CPU still can't handle Veryfast at those settings and you're getting 90%+ CPU usage total in your Task Manager, then switch to NVENC and raise your bitrate to 3200 or so but this will also depend on what kind of content you're streaming and how much movement there is on the canvas.
If you're streaming to Twitch, then 720p30 at 3000-3500 bitrate is absolute most you'll want to go for anyway, unless you've grown quite a bit and you're serious about streaming and growing.
You should try to stay below 75% or so of your total realistic upload bandwidth and you have 5 mbps upload. 70% of that is 3500 bitrate so you're in the clear.
If you find your quality isn't that great on stream, kick up the bitrate to 3500. Games like PUBG have a lot of movement that can bring down the picture quality when you're moving the camera around a lot or using the vehicles.
