Honeymoon Help!

Ok so I booked the flight for my honeymoon and much of the trip so far. I need some help regarding how many days I should spend in each location. Here is how it looks so far. Flight from NYC -> Rome Sept 19-20 Day 1 Sept 20 - Ambasciatore Palace Day 2 Sept 21 - Ambasciatore Palace Day 3 Sept 22 - Ambasciatore Palace That much is settled and we have time to plan what we will do while in Rome. My main question is regarding the next leg of the trip. I originally decided on 3 Nights at Borgo Scopeto Relais which is just outside Siena and then 5 nights in Florence. I now want to flip that and do 5 nights at Borgo and 3 nights in Florence. Any thoughts on this? I figure that we can rent a car and do day trips all over Tuscany while at Borgo. It would look like this for the remainder of the trip. Day 4 Sept 23 - Borgo Scopeto Relais Day 5 Sept 24 - Borgo Scopeto Relais Day 6 Sept 25 - Borgo Scopeto Relais Day 7 Sept 26 - Borgo Scopeto Relais Day 8 Sept 27 - Borgo Scopeto Relais Day 9 Sept 28 - Florence Day 10 Sept 30 - Florence Day 11 Oct 1 - Florence Day 12 Oct 2 - Venice
Day 13 Oct 3 - Venice Also, Sept 27 is my birthday so I would love to do something exciting and splurge a little bit.. Any suggestions for a birthday excursion or site to see? We are going to be doing a lot of site seeing so something out of the ordinary would be best. Any help would be greatly appreciated and if you have any reccomendations for Venice hotels that would be an added bonus. Thank you for your continuing help!