Playmaker can do this… but you'll need to break down each function into states and actions, and a little geometry – something you'll need to do anyway to get the game mechanic you want.

your planet can be a prefab sphere, it's radius can be the size of the planet. Object placement on the surface could be nesting the gameobject at the center of the planet, then translating it the radius until it 'rests' on the surface (or above the surface in orbit).

You might treat your planet's map as a grid and store the positions in an array, or work out a polar coordinate system, or quarternians…. Assuming your resources are procedurally generated, the same system that changes the map colors can be used to test for a hit….

Playmaker is just the nuts-and-bolts, you'll need to approach each mechanic by breaking it down into very small steps.

I mean, exporting a skinned mesh sounds like boss-level super powers, hahaha

but the Editor export FBX does work well with skinned meshes (my experience). I'm guessing that what works for skinnedmeshes would also work for static meshes…

I personally would find a use for both, ha!

  Yay! Thanks for telling us how it turned out!

you can create Unity objects that don't get destroyed when the scene changes.

There is a PM action: "Dont Destroy on Load" to do it.

Is the switch from worldspace to self intentional?

Maybe get the angle to the player, and reverse that?

But I can't really understand how I can do this with a visual software.

Hi… this is kind of a broad question, so I'll try to break it down a little so you can start looking for your answers.

Most of of what you describe is a 'character controller' for Unity. There are many 3rd-party available, but also some provided by Unity (I believe there is a 2D character Controller in Unity's default 2D platform example (the one with the UFO). This will actually cover most of your needs and it's a great place to start. (some controllers are 2D sprite-based, some are 3D figure-based).

You can do the basic setup without coding or Playmaker, and there are tons of tutorials (without Playmaker) for very beginners. You'll want to watch/learn the basic concepts before trying to make your own. Things like running to the left/right, jumping, etc are built-in

Playmaker isn't exactly visual coding, it's a function state machine… very like your description of setting up a state, reading inputs, and transitioning to a new state.

Getting started, once you understand the basics of Unity's systems, Playmaker will allow you to take control of those systems, spawn enemies, create simple behaviors and AI with states: "detect when player is near, and switch to attack-mode" for instance.

I recommend looking at a few of Unity's official tutorials to get the basic concepts (how Unity calls everything) and then search for PM tutorials – I found several but you will know the kind of tutorial you need once you understand some of Unity's terminology (and there are quite a few)