Thoughts on my itinerary

I'll only answer your first question:
Yes, the days for the destinations look very reasonable.

Yes reasonable, even sensible.

I would arrive at the next destination in time to check in and have an evening walk before dinner, getting oriented. Your evenings in May should be pleasant and the light good enough to allow you to get your bearings in Florence and Rome when you arrive.

By booking tickets in advance - and now is not too soon - you can save €€ but tickets are not refundable so be certain of your commitment. I would recommend buying a full price refundable/changeable fare for Milano to Venezia as one has to allow for the possibility of a late flight.

Most hotels, B&Bs will hold bags for you. Just verify they will be present when you want to pick them up. Not all desks/hosts are there 24x7.

That is a wonderful itinerary and you are giving the cities enough time to explore. The trains are a great way to get around and if you get a sleeper room, you can take night trains and sleep so that you can have days open for roaming. I would go ahead and get a railpass before the trip and yes, if you plan to use the sleeper rooms, reserve them (even if you have bought the Eurail pass) in advance.

Terry Lynn, I am sorry to contradict, but night trains with sleeper cars do not make sense for this itinerary. I am not sure if they even exist! The longest change of location is 2 hours between Venezia and Firenze. Also, the Eurail pass does not make sense as it is only 3 point-to-point trips which in Italy are easier and cheaper to do as point-to-point. A pass will cost more, especially if Dmal buys his tickets in advance for the super economy discount.

EDIT: Longest change of location is 3 hours between Rome and Milan.

What Laurel said Is 100% right on, she is one of our best sources of travel information on Italy, and as she currently lives in Rome, she has a lot of great ideas and recommendations especially about Rome. I myself have much more limited experience, but have recently been to all the places you mention. About trains, I make these suggestions: (1) try to travel in the early afternoon, like leaving maybe 2 to 3 pm. This way, you will have a full morning of activity in the town you are leaving, and will arrive at your new hotel in time to check-in with your room ready for you, clean up, and at least take a nice walk before, and after, dinner. This way, you can either have lunch before your train ride, or get food to eat on the train. Dinner is generally quite late in Italy, just beginning at 8 or even 9 pm or later. Many restaurants, but not all, do not even open for dinner until 7 or 7:30. (2) you can save a lot of money by getting discounted train tickets on the Trenitalia web site, but only well in advance (like now), but that locks you in to a firm date, time, train and seat, and you cannot change that. Personally, I like to save major money on transportation, and like that my schedule has some firm structure to plan around. There are many, many things to see and do in each of these wonderful locations, and if you share your particular interests (art, history, outdoor activities like hiking, cuisine and wine, less touristy neighborhoods, etc), many people here will offer plenty of enthusiastic recommendations, including for restaurants. There are some sites in these cities where advance reservations are either required or advised, including to avoid long lines. The RS 2015 Italy book is a great place to start planning your travel and activities in these locations. And my final tip here, my motto in Italy is "when in doubt, have a gelato!"

I will only comment on the comment made regarding train travel. A rail pass makes absolutely no sense for this type of itinerary. Each of your 4 legs will cost 19 Euros if purchased from trenitalia. This is vastly cheaper than a rail pass. Eurail is also a ticket reseller and frequently doesn't have the most current prices or schedules. Please check this site for the best information:

http://www.seat61.com/international-trains/trains-from-Milan.htm#Milan-Italy

The €19.00 2nd class/standard fares are tough to get. Be ready to hit "buy" 120 days in advance. By 119 days in advance for high traffic routes in high season they can be gone.

Night trains are being discontinued. There was once a night train between Rome and Milan, that took a long route through Pisa and Florence and was slow as a turtle in order not to arrive too early in Milan. But now that, for example, there is a fast train leaving at 6am from Rome and getting in Milan at 8.55am, even before most offices open, the customer base of business travellers for night trains and internal flights has mostly evaporated. Fast trains are the way to go, now.

I like to travel in the morning, but that's my OCD. A better plan generally is to travel in mid-afternoon to arrive early evening, as Laurel and others have suggested.

I would never take the last train of the day - things can go wrong - and I prefer to arrive early enough so that I am not wandering around pedestrian areas in the dark looking for my hotel.

You all are amazing! Thank you everyone for the feedback and re-assurance of the game plan.
I'll gladly take everyone's advice into consideration. Thank you all again!

Dmal,
Your itinerary is well planned, except I'd spend the first and last night in Milan or the last two nights there, eliminating one night in Rome.
I agree with a couple of travelers above on taking trains not later than 3:00 pm; point to point are half price than the Eurail Pass even when buying the tickets one hour or one day before departure; I have not found a hotel or hostel that did not store my luggage
Buon viaggio:)

I disagree with the previous poster.

I would not take away a night from Rome.

Your itinerary looks great the way you've planned it.

Arrive in Milan & go straight to Venice.

You realize that 3 nights = 2 full days; 4 nights= 3 full days.
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For your last night in Milan,try to stay near the historic center (near Castle Sforzesco) as the Malpensa Express trains from Cadorna station to the Malpensa airport are faster than from Milano Centrale. (30mins. vs. 52 minutes)

Just curious....why are you not flying out of Rome?

thanks everyone for your advice!
great question, I'm doing a round trip from Milan because I was lucky enough to purchase a direct flight with emirates for $400 per person, it only went to Milan though.