I just wanted to make sure I am not missing something. I plan to buy point to point tickets on Eurostar, rome/florence and venice/rome. I am nervous about not being able to get a reservation when I get there, but I cannot purchase the reservation from here. Correct?
If you're buying point-to-point tickets, then on the trains where reservations are required, you'll get one as part of your ticket purchase....you'll need to specify a date and time of travel. If train reservations are optional, you'll be given the choice. If train reservations aren't necessary or accepted for trains (usually some regional and most local trains), you won't be given any choice. Check the various websites where you'll be making your purchases...those with reservations will come with a car and seat assignment.
For major trains or in peak travel season I highly advise seat reservations. When you first arrive at what will be your next point of departure, keep your eyes open. If line at train station is not too long, buy there. Or, keep your eyes open and pop into next travel agent office you see. If you are able to buy them from trentalia on line, do so, but the website did not work for me. As long as you are confident of travel date and time, buy ahead. Remember, they will book more tickets than seats available, and if you don't have a seat reservation you will stand.
We were also nervous about waiting until we got there and are leaving next week! There are 8 of us traveling, so I had trouble using Trenitalia's website because we needed 8 tickets and it would only let me purchase 5 (or maybe 6)...but its a great site with no surcharges..you are buying direct!
http://www.trenitalia.com/en/index.html
My travel agent's fees were higher than I wanted to pay, knowing Trenitalia's fees from using their website....so I used a Rick Steve's recommended Trenitalia agent www.discoveritaly.net and they couldn't have been more wonderful. My tickets (Eurostar comes with seat reservations included in price) were Fed-ex'd and I received them in a day or two! Franco was helpful and had great follow-up. Good luck!