Parla inglese?

So next week my family goes to Italy (OMG OMG OMG OMG OMG OMG OMG OMG so excited!) I've finally talked my mother out of renting a car and driving to Rome from Venice (she's distrustful of public transportation; it's the control-freak in her)and it looks like we will be taking Ryanair. (Did Ryanair always charge to check a bag? Somehow, I don't remember that.) So, a few questions:

1. Have any of you left from the Venice-Treviso airport? If so, was the Ryanair shuttle relatively reliable?
2. Do you remember if they sell tickets on the Ryanair buses or do I have to buy them beforehand?
   
3. We will literally be flying into Rome on a Friday morning and leaving Rome on a Saturday evening. If you could do one thing in Rome during that 24 hours, what would it be?

ETA: Just spoke to my mother. Apparently we are not going to Rome and "don't worry, [she has] taken care of everything." Oh God.

1. If you've been to Venice, would you recommend the Rolling VeniceCard?

I feel a little like we are trying to do too much on this trip (like usual) but I am so excited to use my passport again!