a few questions as I prepare to leave Italy

Only three more days left here in lovely Rome! I broke down and did a bit more shopping today, but from now on I am mostly taking it easy and revisiting a few favorite places. (Plus FINALLY getting to the Roman Forum ... aka the very first place I attempted to go and the only major attraction I've not gotten to even once!) But I have a couple of questions for Roman/Italian readers, things I have not been able to puzzle out on my own:

1) Prego is usually translated in English as "you're welc...