Vadim... go buy a piano. Turn off ALL the auto stuff.
ANYTHING other than this, whether you make your 'machine backing' yourself, or use preset styles, use SMF's, MP3's, styles, loops, laptops, you name it...
YOU ARE 'CHEATING'.
To one degree or another. You are fooling yourself if you want to put any arbitrary 'line' between different DEGREES of 'cheating' (your words, not mine).
Get a piano, or shut up about 'cheating', because you are doing it yourself, in one form or another. That high horse you are sitting on is a miniature pony, in truth...