Is beer as a product in general (commercial/non commercial) taxed in your country? Yes
Are you allowed to produce homebrew beer, that is tax free? Yes
Is there some amount limitation of homebrew beer that you are allowed to produce without paying taxes? 350l, more than that per year is illegal, even if you want to pay taxes
Is there any legal obligation considering for instance an obligation to fill a report or announcement as a homebrewer and send it to your legal authorities in order to be allowed to brew beer at home? No
Jeden den bez piva pravděpodobně nikoho nezabije, ale proč zbytečně riskovat...