Thanks to the people who replied to my post after I bought the pi3!
I launched it without much hassle. It is now connected to my 50-inch plasma TV through the HDMI port. I use it with a wireless mouse and keyboard and I can browse the Internet. Funny, it even manages to play YouTube videos. Almost. The picture is far from good - understandably for such a minute device, but when the screen is reduced to 1/4 of the 50-inch area - which is still a large area, quality becomes more acceptable. Haven't tried this yet, but I suppose the pi3 will work fine with a small PC monitor.
I haven't been able to play music. Volumio is not compatible yet, Windows 10 IoT is not fully functional. I will probably have to wait before the pi3 can play music - but there's no hurry. Meanwhile I am watching various YouTube videos on the Raspberry PI project - find it very interesting. Anybody with an idea what standard music player (Windows-like, not based on prompts) could be used with the Raspbian?
Sources: Advance Acoustic MCD-403 & MDA-503, Pure Sound A-8000, HDD + old notebook + M2Tech Evo Power Supply + M2Tech Evo Clock High End Word-Clock-Generator + M2Tech HiFace Evo 24Bit/192kHz USB-Interface