Hi Sven, it is possible to hide the toolbars, try the plug-in here:
http://kyticka.webzdarma.cz/3d/moi/#FullScreen

For the small scale problem - various operations in NURBS modeling are calculated to a tolerance level, like when 2 surfaces are intersected with each other the intersection is refined until it reaches a particular accuracy level and small objects can be impacted by this. I do have some changes in v4 coming to try and make small objects get the same proportional tolerance as "regular" objects and that may help with this area.

But it is kind of good in general to avoid working at small scales.

- Michael