Questions about Italy Data Plans

[Andiamo]

Hello,
Can anyone help me? I'm trying to help my over-70 parents figure this out for their annual trip to Italy.


1st Question:
I already have a TIM sim card that we use every year--have had the same phone number since 2004.
Do I need to get a new SIM and new phone number in order to add a prepaid data plan, or do I choose a different type of ricari card?


2nd Question (multipart):
I understand having to activate the data plan. But do I de-activate it on days I'm not using it (can it be turned on and off at will, and should it be?) Or do I just deactivate it when I'm ready to leave the country?
What happens if I forget to deactivate it?
(If I buy it at a TIM store how will I know if they've already activated it?)
DATA FOR DUMMIES PLEASE.


3rd Question:
What is the best TIM data plan to buy, if we only use it for a translation program that needs to access a data network to perform the translation?

There won't be internet browsing.

Thank you so much for the help.

[Effendi]

You can use your TIM card, no need for another one, all TIM cards are pre-activated for using data too.
Data plans are usually monthly or weekly and they are automatically renewed every 30/7 days. You cannot switch them on or off on the days you use them. It's important to turn the offer OFF since otherwise you'll run out of credit and some operators also go below zero €.

I have no idea how much data your parents need every day. I think an option with per KB billing would be better rather than the time billed ones. So TIM is not a good choice.
If you are satisfied with TIM's coverage you can use COOP or Noverca virtual operators.
Otherwise I'd go with Wind.
All information about data in Italy is here:
http://www.prepaidgsm.net/en/italia/data_italy.html