If it works, I would suspect there might be issues getting the anti-halation dye to wash out - the dye is water-soluble, but I'm not sure what the min. temp. is for it to wash out.
I mention this because I was trying to help someone in England over on p.net who tried to do semi-stand development using water immediately out of his cold water tap. He did the semi-stand for an hour, but his dye didn't wash out (Tri-X and HP5+). I've done it with both films using water at room temp. (about 20 deg C), and the dye washes out each time without issue (I usually to a 2 hr. stand, but I have tried 1 hr., no difference with the dye). (He also had issues with thin negs, which may or may not be temp. related, not sure.)
As for (b), usually the risk mentioned is reticulation, but having never tried it I don't know what the required temp difference is.