Yeah! This was another great realization from KSP — figuring out that the naive way is possible, but the delta V required to do it is absurd.

Here's a video of a KSP speed-run to the Mun and back in 2 hours using this method (with 10K m/s total delta V — I think Jeb takes 34Gs at some point, which is about 5-10x what normal astronauts feel): https://youtu.be/0dx7ScJSAwo

That is only possible if you have engines and fuel capable of sustaining a powered flight. We puny humans so far don't have it.

You don't need to sustain thrust the entire time you just need to reach a significant portion of escape velocity energy early in your launch (which is what most launches need anyways just this time you need slightly more energy than the efficient way). This is not something we have trouble doing, for reference we launched New Horizons directly into above escape velocity speed with an Atlas V rocket. The only reason we haven't done that kind of launch to the moon in real life is it's far cheaper and more efficient to do that "normally" not because we couldn't.

Nah the easiest way is just to get in low kerbin orbit, timewarp until you see the mun come over the horizon, then burn prograde. No manouver nodes necessary.