If you want a terrible focus tree then play as the US.
Hahahaha... no, the US focus tree does screw the US Badly in the beginning, but it is by far the best lategame focus tree, bar none. Six technology slots, a rediculous amount of bonuses through spirits, and other things. The only focus tree that might be better is the British one.
I wrote some guides on National Focuses a long time ago, the information is old but is, 99% of the time, still correct.
Here is one for National Spirits
Here is one for technology bonuses
As you can see, Italy's focus tree is actually the best in the game when it comes to technology bonuses. This allows Italy to get an amazing tech lead in almost anything, especially when it comes to navy.
The only objectively bad focus trees, of the old ones (I have not looked at the DLC ones, holding off on DLC until Paradox fixes the game), is Poland and France. Poland's suffers from being a watered down generic with nothing to show for it, and France is just a pile of maluses with the late-game bonuses being weaksauce.