oh - I had a different layout in gpsmapedit with 0x13 set to invisible and not used to opening gpsmapedit from my laptop. So the map was actually correct:
is now fine - though of course the visible rendering is not really representing how it looks in reality - but broken routing is fixed.
as you said is still spiking - and actually with my style in that case also wrongly ending up in 6 routable lines. For me really a simple remove all semi connected ways at minimum length filter would be fine. I would just remove clutter of micromapping.
As for the roundabouts.
a bit strange that it gets split into 2 ways. Routing seems fine. (the NNE section of the roundabout between the exit and entry is separated)
actually looks much better then with older versions of mkgmap. Looks pretty round - with a 3 month old mkgmap version (sorry don't have unpatched to compare) it was not very round. Routing is fine.
Although here the north section is split off into a seperate way- it this a need for roundabouts?
Felix