With regard to finding a way to have Zotero connector work with Safari, I have:
(a) deleted a reinstated Zotero (from the recommended website), but that didn't work (b) used the trick of Safari-->Settings-->Advanced-->Developer mode-->Allow unsigned extensions,
(a) deleted a reinstated Zotero (from the recommended website), but that didn't work
(b) used the trick of Safari-->Settings-->Advanced-->Developer mode-->Allow unsigned extensions,
and that didn't work either.
Any other suggestions?