Thank you for your awnser!
In addition to question 1 - and how about shapes and designs - I won't add any logos and brands but I will do for example SG guitar or Fiat Panda (sorry for same examples ;P) based on real life objects or references - It's legal? I've read somewhere that someone can sue me for that too.
In addition to question 2 - So in short - if I earn more than value called "tax free value" (I think I can translate this like this) in one year I must pay tax at end of the year for amount that's higher that tax free value in my country. Shame that Poland have one of least TFV in the world :< Sorry for that I needed to visualize that but for sure I'll contact an lawyer.