10 nights in Umbria before Rome- help please

First, stairs: unavoidable in some places, but often there is an alternative ramp-type street nearby. An incline, but not always steps.

Orvieto is flat around the main piazza and in a few other places, but it also has some steep streets. Five nights on Orvieto seems like a lot, since to take a daytrip from there you have to get down to the funivia that takes you down to the train station. I would spend three nights in Orvieto and two elsewhere - Assisi or Todi come to mind (but the bus to Todi does not run on Sunday). Gubbio might be another choice for a couple of nights.

For your flight out, you can stay in the Centro Storico in Roma and get a taxi to the airport (reserve the night before).

In many trips to Italy we had never been to Ostia Antica, so we added it to the end of our trip last spring, staying in Lido di Ostia. We arrived one afternoon, spent the next day at Ostia Antica, and went to the airport the next morning for our flight. Lido di Ostia doesn't have anything particular to recommend it, but the hotel arranged our shuttle to the airport and it was extra-easy.

Do not go to Assisi. It is the most hilly place I've been to in Italy, with hundreds of steps in the historic center.

When I think of flat, I think of Bologna, which I loved. It's a great base for day trips (it's a train hub) to other flat places: Ravenna, Ferrara, Padua. Those are the only ones I've been to. Give the guy a break and spend 4-5 nights there.

Orvieto is a good choice for a couple nights on the way to Rome. It has enough sights to fill a couple days, though some of them involve stairs. You could even go here for your last 2 nights, then take a late afternoon or evening train to Termini and on to FCO for your airport hotel.

The centre of Perugia is almost flat. Down to the bus station is mostly done by escalators. It is a bus trip to the railway station below.
Assisi is a place not to be missed, but it is hilly. Best done as a day trip from Perugia by bus or from quiet and agreeable Foligno by train (with a connecting bus from the Assisi railway station to the basilica).
Spoleto is a beauty, but a lot of stairways. Also best done as a day trip. Be prepared for a EUR 15 taxi ride from the railway station to the city centre.
I can't remember any significant stairways in Orvieto, but I have probably missed them. Take the funiculare opposite the railway station to reach the city centre.

From the top of the funicular to the core of Orvieto's historic distict is an uphill walk, mostly the first few blocks near the funicular station. I'm nearly certain there's a bus. The central part of the upper town is pretty flat. There's a branch of the tourist office right near either the bottom or the top of the funicular station; I think it's at the bottom. If you should decide to spend 1-1/2 or 2 days there, the city card might pay off for you. In addition to being a very pretty place to wander around, Orvieto has a number of pay-to-enter sights. Ask about the walking tours before committing, though; at least one of them involves a lot of uphill/downhill.

If you get as far north as Padua, you're very close to Vicenza, which is also flat. I haven't been to Verona.

Verona is also flat - and we loved it.

Orvieto: Your funivia ticket is valid for the bus up to Piazza del Duomo, the TI office is in the Piazza.

hmmm I guess the hill towns really are hilly, with various stairs and inclines- fancy that.

Funny to hear Bologna mentioned, as we've been before and want to return. Also enjoyed Verona.
Lots of good info here- thanks everyone.