Good Stuff ^^ ...
That's exactly how I go about playing 'free-style' when I'm not playing covers or such, or just chilling out, with 'empty' rhythms that correspond to stuff only I can hear in my imagination. Up the tempo a little, change the accent, throw in a fill or 'falling down stairs' drum lick, cool it down and start again... I get lost when playing (drums, stoopid... ) by myself; it can go on for quite a while until I suddenly find that I've forgotten to 'breath' again, and have to stop for a rest, exhilarated but exhausted.
Good Stuff...