If you run that outlet of the top hat into a bottle, it will certainly blast any oil in it out of it and will go everywhere.
Personally, loose the filter as that could be causing a slight back pressure causing a rough idle. Try it with it off and see what happens.
The main thing to have blanked off is the vac line out of the throttle body and the small line that runs from the āsā shape hose that links manifold to the ISV.
Make sure you have a nice 25mm pipe coming off the crank breather to atmosphere, bottle or better a catch tank.