Oh, sorry! Must have gotten lost in my reply list. 22 is low, but you get used to it fast. Always easier to put more clothes on than having to heal with hot weather. At least that's what I think. Sardinia is super hot, I can imagine. I experienced a bit of that kind of climate when I lived in Malta for almost a year.
Termini is dodgy, no doubt about it. But the place was nice and the few hundred meters to the station weren't that much of a hassle for us to cross. Plus, I am no stranger to sketchy places. I am just checking your posts and sending you some heavy HF19 upvotes... :) All the best!