how can I make a difference between streets that have even/uneven housenumbers seperate or mixed along either side of the street? I would like to use the BAG as a source. Could I calculate the length of the route between housenumbers to find out?

I would try this:

Take the road (lines) and buffer using a Bufferer transformer (cap type none, size up to you).

Then split the buffered area into left and right using the LineonAreaOverlayer and output Area.

Then use the PointonAreaOverlayer to list the address points inside the buffered areas.

If those address points are only even or odd you have no mix, else they are mixed.

Hope this helps you get started.