Q2. Boccni vs SSE.
Go to the one with scholarship. If both of them have / don't have, go to the country you like more. Same tier. I prefer Sweden way more than Italy for language and culture issue.
Q3. UK vs EU.
Depends on how much you want to stay in Europe for a job.
Given "还没决定到底是回国还是留国外", it is 100% back home if you go to either school in UK.