Waiting in line
Well, nobody else could answer so I'll answer myself from the experience we had, and hopefully this can be helpful for someone else: Short answer: You cannot see the Duomo, Baptistery, Bell Tower and Uffizi before lunch!
Everybody standing in line around the Duomo have got tickets! There are no ticket sale at the entrances; so don't hope to pass the queue!
The long answer:
- Climbing the Duomo: We stood in line for maybe 15 minutes, and found that there were people both in front and behind with tickets for other time slots than ours, but that didn't seem to create any problem for anybody.
- We didn't try to enter the Church itself after the Climb, because that was a really huge line. Expect to spend the best time of Your morning or afternoon there if you want to go inside.
- At the Uffizi gallery one of us waited in line while the other picked up the pre-booked tickets, and it took little less than half an hour to get in. You will need some time through security check and ticket check inside though; it took about an hour before we actually entered the Exhibitions.
- Baptisterty/Bell Tower: We went to the see the Baptistery and Bell Tower the next morning. There was hardly any line at all at the Bell Tower around 10 o' clock, - when we passed one and half hour later, the line went all along the side wall of the Duomo.
Looking forward to returning to Florence on a later occasion!