Nothing wrong with changes especially if they are important and can add content and additional flavor.
Depends. Where there are plenty of things the game could use that add more flavour and content, then wasting time on what is (I believe to be) a tiny and relatively meaningless part of the game. It requires a disproportionate amount of effort for the actual benefits and (in my opinion) will quickly become redundant, the changes contained within other developments to the systems (which already represent it well enough anyway).
Further more, there are plenty of other similar threads with people asking/demanding various changes/additions to (their) nations, by considering this suggestion on its merits and then deciding in its favour would create a precedent that would result in those similar suggestions with equal merits having a right to be included. Such additions should only be made as mods or after all the much more significant additions have been made.
I would like to clarify that I am not arguing the exclusion of any improvements to Tuscany/Florence at all, just that such improvements are better served by waiting until a later date, best placed as part of an Italian DLC that includes Italian Republic and Monarchy governments, unique events and special papal interactions for all the Italian states. It would be much more beneficial (more can be added) and efficient than adding lots of Tuscany specific improvements that will (hopefully) later be made redundant by all the improvements that Milan, Genoa, Venice and the other states all deserve.
The argument being that if we add Florence, which would not impact performance significantly enough to be notable, then we would also have to add X number of other tags, which eventually would add up to a performance issue. I don't buy this argument because the devs aren't idiots who don't know when to stop adding new tags. As evidenced by this thread, they take every addition into careful consideration based on its individual merits rather than applying blanket rules for what "deserves" to be added.
It would not be a blanket rule.
If Wiz adds all the suggested Tuscany changes suggested in this thread to the game (Unique Government, extra Idea Set, Formable tag, events and papal interaction) based on the merits of the gameplay effects of such a change (what Wiz asked everyone to argue) then logically, any other nation with similar or more gameplay and/or historical relevance would gain just as much from similar additions to them. Rather than looking at each petition for changes to every nation individually, Wiz should look at where the high concentrations of such states are (Italy, Balkans, Germany for example) and work on later DLCs that add those changes to ALL included nations at once.
For example, an Italian DLC could easily add new government forms to the Italian states, add new ways to interact with the Papal states and add mechanics that simulate the outside political influences of Spain, France, The Ottomans and the HRE on those states and the resulting conflicts it caused.
"oh no, I sure hope the developers don't listen to the community; that might encourage the community to share their ideas. It would be terrible."
Fortunately the developers are capable of distinguishing between sarcastic straw man arguments and the reasoned discussion going on in the rest of the thread.