Makes sense for Pogba to be the #1 item on their shopping list. In fact, it'd be stupid to not have him as the #1 target.
They need two world-class CMs and need to sign a good CB for a change.
Toure is finished and won't stay, Fernandinho is decent, their immediate backup, Fernando, is...lol. Out of the top CMs who might be obtainable, makes sense to go for the best of best.
For Pogba, it makes sense to remain in Turin for another year and, then, move to Barca and win many trophies with them. Could use another season at Juve to finish his development, and Iniesta will be 33 in 2017-18. Doesn't make much sense for Barca to have one of Iniesta and Pogba (both play as mezzala) on the bench next season.
Barca not so much, just the past 10 years. It will fade, while Real will not.
They won't thanks to Cruyff and the changes and style of footy (compliments Spanish players well) he implemented at La Masia. And they're obviously more than stable financially.