I mean you also make a convincing argument cause i think theres meny cases where a language has its own ides about whats a phoneme and what isnt, and the pretty artificial approach of “just looking at minimal pairs” is often pretty nitpicky. As for ɧ, there are three reasons for why it exists. First, sweden is very much a first world, western, rich country, so if they have a unique feature its going to have a high chance that its implemented in a standard. Second reason is the dialectal variation that you mentioned, in some dialects it reduces to quite simple phonemes like /ʃ/ for example. Third reason is that experts arent even really sure how its produced(yeah i know, wild). Like they literally dont know how its articulated. But yeah.