Seems like I found a finally stable setup. The previous wasn't stable after all - the driver tends to crash on them. Doing stress tests for now to check that everything is OK. You'll need the Notebook Fan Control though to set the GPU fan at full speed, else it is a little dangerous to close the lid, lol, overheating occures (dunno why in auto mode it never spins the fan to it's full).
I'll post the 3d mark 2011 score a bit later, it featured a graphical score of about 9290, but I'll rerun the tests to check it again that everything is allright.
The settings probably ARE a little dangerous, but now running for about 1 hour of stress tests I got no driver crashes, nor black screens, nor artifacts. Seems to be pretty stable, but will run it for longer.
I think the settings I'll post are probably the highest possible while being stable. Just wait a bit until I end all the stress tests.