If you care to retain an Aristotlean viewpoint, and I accept that not everyone does, then there is some information here: [url]Card & Board Games ARCHIVE & LINKS].
A blinding light is not lumen, but lux. That would not blind anyone beyond the limits of the circle, and would need to penetrate the MR of anyone within the circle.
I don't believe -- but am away from sources just now -- that heat is a form of species. Heat is a quality derived from an item's substance; basically the presence of corpuscles of elemental fire. As a fire burns, fire corpuscles escape into the air, imparting it in turn with the quality of heat. Those fire corpuscles are magical in the situation under discussion, and would remain in the ring. Anyone inside the ring with MR would not be warmed.
I reserve the right to change my opinion on this after consulting my Aristotle and Avicenna!
Edit: so now I've done a bit of digging, and my statement about heat above was not quite right, but correct in its conclusions. A body is affected by both the form (i.e. species) and matter of a sensible object, but the sense faculty is affected only by the species. In practical terms, if you touch a hot object you get burned by the matter and you feel the pain from the species. So heat is perceived by the tactile sense as species. The ring would not limit the radiation of species, so the magus would still feel the warmth, however he would not actually get warm, because the matter (fire corpuscles) are limited to the ring. The same would be true if he were inside the circle and the magic had insufficient Penetration for his Magic Resistance.
So when you are hit by a Pilum of Fire and your parma successfully resists its effect, you will still feel the heat of the flames (i.e. the species) even though they can't damage you.
Mark