I wan't to express, that I disliked Rick and Morty season 3

[Homeless Nutter]

Personally, I never thought that Rick turning himself into a pickle was in it on itself that wacky, on the other hand his reason to do so was what I truly found ridiculous. The show it's sci-fi, which means that the natural laws are different from the real life.

Actually - that would be fantasy. Sci-fi generally builds on our existing reality, using technology and theoretical scientific and philosophical concepts to explain what appears to be supernatural. The Pickle Rick episode is pretty difficult to explain in those terms. It's mostly just wacky cartoon fun.

When making sci-fi, if it's not for comedy, you have to follow your rules. In Rick and Morty a rule is that kids are a lot like the ones in real life.

Yes, for the most part. But in the show's multiverse there clearly exist exceptions to every rule. And most Ricks seem to be aware of that. If there can be mentally deficient Ricks, there can be particularly mature, or gifted Mortys - all of which is consistently depicted in the episode. You may find it unrealistic, but again - it's a cartoon.

Also, I think that it would've make a lot more sense and it would be a lot more interesting if evil Morty, instead of becoming the president himself, was controlling a leader which was a Rick. 

Maybe. But wasn't that kind of what happened when Evil Morty originally appeared? Perhaps the creators didn't want to repeat the same scenario.

Also, I don't believe this is an actual Futurama rip-off.

Isn't it, though? Well, not exactly, but the idea behind both shows is largely the same: a young, unremarkable guy has wild adventures in space, exploring various sci-fi and fantasy concepts, facilitated by a simple sci-fi trope - a journey to the future, or an eccentric scientific genius. Both shows have an episodic format, allowing for different adventures to be largely unrelated and for things to go back to "normal" at the end of each episode, but still retain some continuity and character development through overarching plots. Both rely heavily on pop-cultural references, both for plot and humor. And even though "Rick and Morty" is way darker and cynical, the humor in both shows is not all that different.

And there are some striking similarities between Rick Sanchez and Bender Rodriguez, but maybe that's just because they're both alcoholics.