there really should be an option to turn off visible orbits...
There is, he just isn't using it.
This was the hardest Project Beast video to watch. They're in perfect position for rendezvous for like half the video but they just don't know what to do next. Then when they do get close they want to slow down, but instead of pointing retrograde they point target/anti-target.
Their re-entry was funny though. They finally realized 30-35 km is the point of no return when it comes to re-entry. You can be coming in from the far reaches of the solar system going super fast, but the planet will still pull you in if you get that deep in the atmosphere. They would've been absolutely fine if they didn't land on a mountain. They also would've been fine if they put a drogue chute on their craft. A drogue chute opens at a higher altitude and speed vs the normal chute. The idea is to use the drogue chute to slow you down fast enough so you can deploy your main chute faster.
And their Kerbals Ark ship can definitely get to that last Kerbal. That thing has so much fuel, I think you could go on a solar system tour with that thing. It would be even better if Vinny replaced the engine with a more efficient one. He keeps using that rocket on everything, if only he realized its one the shittiest engines to use outside of atmosphere. And Vinny had the idea of putting a space station between Kerbin and the stranded Kerbal. That would mean he would have to dock. If he has so much trouble just getting close to something, no way will he be able to dock two vessels together, its probably the hardest thing to do in the game, in my opinion. Plus the idea of a station there wouldn't work. Kerbin, the station, and the stranded Kerbal would all have different altitudes in their orbits around the Sun, meaning they're going different speeds. They would quickly become out of sync.
The way to get that last Kerbin isn't that much different compared to how they've been doing it. Its just that now you have to break out of Kerbin's sphere of influence and orbit the Sun, which is slightly more delta-v than getting a Mun encounter. Then its just the same process as the last two times, but now you're orbiting the Sun, and the time scales will be longer too. Getting back into Kerbin's influence will also be a pain in ass, and probably take a long time.
They really should have just done one video of them rescuing one Kerbal, and then moved on to trying to land on Minmus or other planets. Minmus is actually easier to land and return from than the Mun is, and people like Scott Manley say to go for the Minmus first because its easier. I think a Kerbal can even get into orbit with just their EVA pack.