As far as eddy currents are concerned I think that in this case it's NOT a big issue; magnets indeed are totally steady compared to other metallic/conductive parts and as a consequence I don't see how they could generate.
Of course a small amount of eddy/stray currentes are always present but non in this case.
You are right I might improve the magnetic circuit BUT that was not exactly the purpose of what I did, in other words I didn't want to make a generator but simply a 1W-Machine; mechanical/gravity power on one side, electrical/magnetic power on the other side, everything has been done just with junkies that I had in may garage!!
However,talking about the magnetic circuit, look where magnets are mounted: there is an aluminium disc (totally amagnetic) with twenty holes just to secure the magnets and the magnets themselves that stay attached to the brake disc that, in this case works as a magnetic coupling among the north-south magnetic poles.
On the other side the coils are magnetically coupled by a simple very rudimental peace of iron .

All that might sound a bit preistoric ... but it works !!