Personally I don't like the idea of changing the coach year in year out,especially without a good reason like we did with Deschamps. I think we need continuity, to change the coach every season isn't a good thing. TBH Ranieri wasn't my first choice at all. I was pretty sceptical and even disappointed with the choice of our board. But now my opinion on him completely changed and I really like what Ranieri does. Like you said, if the refs weren't that bad and corupt we probably would be Serie A leader right now. Despite I think Ranieri has a great character which suits Juve.
I can't immagine someone like Mourinho in here, he's more suited to these arrogant clubs like Chelsea,Real etc IMO. Most of the Mourinho lovers are arguing with his so called winner-mentality,but in the end he won just league titles with Chelsea and choked in CL(I must admit his CL win with porto was great though). Seriously, it's not that hard to win the leauge title with so much cash available. Maybe in 4 years but now I'm fine with Ranieri.