Is beer as a product in general (commercial/non commercial) taxed in your country? Yes, commercial beer is taxed
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? 200gal (~750L) for households of 2 or more adults, 100gal (~375L) for households of 1 adult. Note that this varies state to state somewhat.
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
On October 14, 1978 President Carter signed a bill, H.R. 1337, which dealt primarily with excise taxes on certain, trucks, buses, tractors, distributions from retirement plans, and permission for certain persons to receive cash payments in lieu of food stamps.
Beer, what about the beer?
On August 23 of this year, Senator Alan Cranston (D-CA) and Senators Schmitt (MN), Bumpers (AR), and Gravel (AK) proposed an amendment to this bill (Amdt. No. 3534). The amendment called for equal treatment under the law for home winemakers and home beer brewers. Brewing 100 gallons per adult, up to 200 gallons per household, would be permitted for personal use. The term “brewer”, used in current federal regulations and taxation was clarified to mean a person who brews beer for sale or who brews more than the legal amount. Homebrewers do not have to register or pay taxes on their 100 gallons of personally used brew.
Carter Passes Homebrew Legislation: excerpt from Zymurgy, Vol. 1 No. 1, printed December 1978
Not sure if this will help or not, but it's worth mentioning.
One serious benefit to the relaxed homebrewing laws here in the States is the direct influx of cash to the national economy. Innovations by home brewers who had the freedom to experiment, and later went on to open craft breweries, have changed the face of the alcohol industry. The influx of new businesses introduced new styles, ingredients and products to customers which drastically increased the market demand and sales over the past few decades, effectively adding billions to the US economy.
The American Homebrew's Association published an article on "
The Economic Impact of Homebrewing
". Homebrew shops alone generate 764 million USD in revenue and the estimated impact of home brewing in general being 1.225 billion USD and 11 672 jobs.