I'm planning to fly into Rome and stay for 8 days. What trips are reasonable to take in this time period? I wanted to check out the Tuscany region as well as Venice? Any advice?
Rome needs several days all by itself. If you can get a night train to Venice, go for it, but stay at least 2 days (3 is better). A quick stop in Florence with a side tour to a smaller hill town is the most you'll have time for in Tuscany. With only 8 days, I think you may need to choose Tuscany or Venice, but not both. Rome is wonderful, better than I ever expected.
You don't say how you are travelling but keep in mind Venice is between 4 1/2 to 6 1/2 hours by train from Rome depending on the train you take. Florence about 1 1/2 hours. You may be better to do Tuscany from Rome and then base yourself futher north in or around Venice to see it.