Let's try to answer all your questions!
1) With TIM usually you have to wait some time before the sim is active. It can be half an hour or a couple of hours. Unless they changed their system. So you should wait a bit before checking the sim. And then you probably have to wait some more time for the data package activation. BTW you always receive an SMS telling you the option is active.
2) I hope they should!
3) Voicemail should be very easy to use, if it's in English. BTW in Italy nearly no one uses voicemail, so expect quite a basic service. Anyway I think there's no sense to use voicemail in Italy!
4) No way
5) TIMxSmartphone MAXI renews automaticcally every 7 days. No one will charge your credit card, it's a prepaid card, if you have credit they take it, if you don't, you stop using the sim-card.