Still plodding along and finding some of the parsing a little ? The hole is getting smaller though. A Q? re 11a. Is the sterilisation what one might do to kitchen surfaces? I can make it work with rather a lot of ignored letters ie 5.
Back again! I think I have valid answers for everything apart from 8a which would help a great deal with the jigsaw puzzle. (I don't think I can make the hole symmetrical - is that OK?).