Venice is good to wander, however stay in Venice - not near Venice. BA do some cracking flight and hotel deals from time to time.
....but you can't see the Coliseum in Prague. Easy to avoid the sellers. Everyone should go to Rome, don't be put off by idiots.
I cant express more to ignore this person. Rome is one of the greatest cities I've ever visited. The history and food alone make it nearly impossible to have a bad experience. If you're super upset by the occasional gypsy, you're gonna miss out, but then being a bigot will ruin many European destinations. My only thing here would be that 2 days doesn't let you even touch the Rome experience. There's just too much. But maybe good for people who have been to Rome but not Venice yet. Especially since Venice can be mostly seen in one day.
Avoid Venice, it's a theme park with cruise ships unloading 3-4000 people at a time, far too crowded, far too costly, far too touristy.....
Wouldn`t recommend Rome at all- beautiful city, horrible people. Could not believe the number of touts and con artists preying on tourists at all the attractions. Much changed for the worse in that respect at least from years ago. Prague is a much better destination!