Is it realistic for me to take a train from Barcelona to Rome?

Do NOT NOT NOT buy a Eurail pass. Train Travel in Italy is very cheap and if you purchase your tix as soon as they become available on trenitalia.com you can get bargain fares which ALREADY come with seat reservations. Eurail Passes are not usually the most cost effective OR the easiest mode of train travel. Buying point to point is the easiest for your travels.

In addition to the cost issue raised by Tim, consider the implications of having to cross France. If part of that travel is on trains requiring reservations (that would be the fast trains), you could run into a problem if you wanted to make last-minute plans, because the French train company (SNCF) has a quota on how many reservations it will sell to people who hold rail passes. It is possible that you might not be able to get a reservation on the train you want even though not all the seats have been sold.

You can take any route you want between Barcelona and Rome as long as you're willing to buy the tickets. To see the sort of "standard" routes--typically the most time-efficient, do this:

• Go to the Deutsche Bahn website.
• Enter Barcelona Sants as the origin and ROME as the destination.
• Select an approximate date (no later than early June) and a time.
• Click "Search".
• Click on "Show details" for one of the itineraries shown. That will display the connections to be made.
• Click on "Show intermediate stops" after the last connection. That will show all the stops made on that itinerary.
• Repeat the last two steps for other itineraries. As you will see, they don't all follow exactly the same path.

Deutsche Bahn will not show you prices since you will not be taking German trains, but I find it the best website for looking at schedules and stops.

From the French-Italian border to Rome, you can also travel exclusively with Regionale trains which are very cheap, (partly because they are subsidized by taxpayers) and very useful if you want take your time and stop off at various places.

Just to clarify a little bit of what Sam posted. All trains in Italy except Regionale trains require a seat reservation that comes automatically with a point or point ticket but an extra fee with any rail pass. Second, since Regionale trains are open seating (no reservation - stand till a seat is available) you can easily get on and off Regionale trains along your route with the proper ticket. Regionale trains can be a very cheap and easy way to go if you are not in a big hurry.

Yes, it's reasonable to cross that distance with several stops in 15 days, breaking up the 24 hours of train travel time that it would take to go without stopping.

• For the distance between Barcelona and Nice, if you don't have stops planned, then trains take 7h 15m to 9h 20m with one connection. Typical train connection points where you might add a stop include Montpellier, Nimes, Avignon, Marseille, and Aix-en-Provence.
• You can also fly from Barcelona to Nice (or to Pisa and other Italian airports) for a very competitive price (see www.skyscanner.com).
• The rail line from Nice to the Cinque Terre and Pisa runs slower than the rest, but it is the main way to connect those points and does continue along the coast to Rome.
  

Looking Up Train Schedules and Routes Online gives you the DB train schedule link and tips for using it.

A rail pass price comparison depends on the whole trip plan, once it's firmed up. Don't get a pass for just this. If you would use it for additional destinations during your additional 2 weeks, that affects the decision. On the other hand, if you flew from Barcelona to Nice, then that would cut out a big chunk of your train distance and expense, so you'd have to look at what's left.