Lumen, all the special cells are symmetrically placed, so 28a has none.
10d is not in Chambers. A newbie is a deb.
Malone, I agree. But I think 39a should say department rather than region as they have specific meanings in France (I think). And the definition in 1a doesn't quite work for me; it should be a Greek something. Also "in" in 18d is misleading.