Just to make sure I'm clear on this, you're talking about a non-turbo motor here, right?

It's normal to take some crocus cloth to break the sharp edge of the chamber after milling the head, just enough so you don't cut yourself. 1/32, or any visible chamfer, is WAY too much. Without going into an article-length explanation, it has to do with the squish / quench characteristics -- the area where the flat top of the piston almost contacts the flat surface of the head is there for a reason, and exactly how gases are expelled from that into the chamber is critical to efficient combustion. Rounding that edge is destructive to that process. It's not a hotspot at all.

Porting a normally-aspirated motor is an absolutely arcane art. The shape of the ports is all-important. Picture the airflow in the port as a river having to go around a bend. For there to be no turbulence (which is what porting is all about), the water would have to speed up at the outer bank and slow down at the inner bank. That doesn't happen -- you get some turbulence all across the stream, and it's likely that some water will eddy and actually flow upstream in places. Volvo put a lot of work into developing the curve in those intake ports to minimize that turbulence -- you cannot improve it without enlarging the whole port a bunch... and then you have velocity problems with the whole flow slowing down. That's catastrophic in a non-pressurized motor. Leave it alone.

On the other hand, feel free to remove casting marks and anything else like that -- we don't want snags creating local turbulence in the river, so that's all to the good.