Some points I agree, and some don't.
I think most important aspect for Ranieri is that he has to install some character and philosophy on this team. For me he has been too flexible and allow his team to play without any identity, bar Valencia team he managed at his first go, which based their game on counter-attack. That is just as important as players he could bring in to the squad. Its a difficult process given that there many young elements to this squad, but managing Juve is always going to be difficult.
Now in terms of future mercato prospects, I like Nasri. Admittingly, I havent seen enough of him to make proper judgement, but the boy is a real talent. IMO he is class over some overrated his fellow "prodigies" like Nani. A player of his technique, creativity, and flair don't come very often, and I personally think anything over 25-30m Euros is a money worth investing in this prodigal kid given some of the money spent on less prestigious talent. Nasri is someone you want to build your team around. Whether he has the physique to take the heat from Serie A and load of being the fulcrum of the team is another matter. I say leave the kid under your radar for a bit, make CL this year, and buy him next season.
I personally don't like the idea of Makelele to this team. We havent got that registra in the midfield to play compact midfield in manner of Milan. Bringing Nasri or Diego will solve such problem, but whether we can buy them this summer is another question. Makelele still got a good year or two no doubt, but right now, Juve have 2 30+s in the form of Nedved and Camo. None of them have that pace to frighten at this stage of their career. This means placing both Nedved and Camo higher up the pitch is the most logical way of maximising our offensive output. That leaves a lot of gap in the midfield. And Makelele simply doesnt have the legs to that. Sissoko's energy is precisely what doctor orders to this team. That is why I am highly interested in Mavuba as well since he seems to have bags of agility to burn. Beside the possibility of 3 30+s patrolling in the midfield, and the need to buy 3 or 4 replacements next year is something I wouldnt want if I was Secco. But I wouldnt mind buying Roberto Carlos for free. Our defence has a lot of youngsters, and they can definitely benefit from the Champion like Carlos. He is free, so he is available and won't cost too much financial commitment. Savvy transfer I say, the kind of thing Moggi would do himself.
Now I agree with your evaluation on Rosina and De Rossi. Rosina IMO is most talented Italian right now, and I just can't forget how he destroyed Atalanta this season. But we probably aren't getting any of these players, and for me they are exciting prospects but simply not possible as it stands.
A lot will depend on what we do with our senators during this summer. Personally, I think we should sell Camo, & Trez since the prospects of them signing an extension seems low. Buy Milito, Mavuba/Sissoko, Carlos irrespective of what happens. Then spend the money we recuperate on the market on Quaresma, and Huntelaar. And no I don't want Iaquinta anywhere near this team. If we are a bit creative, I guess we could go include Camo to steal Chivu from Inter. I say 13-14m Euro + Camo + Molinaro is pretty good deal for both teams. As for Trezeguet, we should offer him for a straight-up exchange deal with Gila. If they refuse, we can put some cash on the deal make it happen. But no, no Iaquinta thank you very much.