Unity and me are not the best of friends atm

Last weekend I made a start of the game and was thrilled how easy it was to get quite far using Unity (well, the asset store helped a lot also).  Beginning this weekend, where I have to finish the game I am a bit frustrated at the tool and rather than spending my time implementing or making something, I am fighting settings. So the experience is really not that enjoyable as for example implementing the game I made in Dragon Ruby a while back (Svipugong) where the work was quite straight forward. The engine wasn't the problem, it was more what I had time to code. Here the code is super simple (there is basically none), while getting the engine to behave predictably is the main issue. 

Example: Yesterday I spent hours trying to get simple physics to work when the player character jumps. Now, the simple version of this would of course be to just completely control all movement in the player script and be done with it (as I would have done in a non-engine game), but here we have physics, rigid bodies and features that should make this a walk in the park. Just add colliders, click the "gravity" checkbox and then I can just add an impulse force to the player for jumping. This is super simple and a very productive way to get this done. Just that it didn't work. My player falls through the floor..  It doesn't matter what I do, he falls through. I have followed every advice the internet has to offer without success.. And the fun part is that if I add another object to the scene with the same settings it will also fall through unless I make the player kinematic. So: If Object A is kinematic and Object B is not, B will not go through the floor. If I however make Object A non kinematic both fall through the floor. If this is a feature, I am too stupid to get how it works.

I eventually solved this with just detecting the collision with the floor and then controlling the players position within the script but it annoys me that I shouldn't have to. 

Anyway. I will give this a few more hours today and see where I land. More of these endless "change a setting and see what happens since it makes no sense" sessions and I will go for plan B that is to just do this in dragon ruby instead and save what can be saved. Using that is in theory a lot harder, but it is completely predictable.