the ps3 slim has an external power source, no? I figured the reason the fat PS3 had a switch was due to the internal psu, and the opposite for why the slim doesn't. I know the 360 external one still is getting charge even when the 360 is off because of the orange light.
and I haven't checked up on it in a while, but way back when a lot of third party controllers worked with PS2 games and after a patch they stopped working. Something along those lines.