You're welcome, but I rather wonder at this point whether you are not loading yourself down with so much information that it will paralyze you.
Research is good, but to try to plan everything down to the last detail and the last second is, I think, an invitation to disappointment if not to outright disaster.
One hint that may prove useful: Museum and other opening hours printed in glossy brochures are often subject to change. Go to one of the tourist offices and beg for the "orari dei musei e delle chiese" and don't let yourself be put off with one of the brochures. The tourist offices have plain photocopied sheets with the current information, but for some reason they are reluctant to hand them out. Or, at least, that was the case when I was last in Florence in 1997.
So true what you say about the potential for overload, but I've already started to craft a "loose" schedule that provides for some happenstance and whimsy.
Maybe like many here, I don't expect to get to everything on my list, but feel its good to know my options.