Well with Kimi u know what u will get i gues with the advantages u describe, but i would still prefer the young up and coming over Kimi who is not gonna make a alot of mistakes but also on the long term does not have the potential to grow into the next Schumacher/Alonso. Also when Kimi and Felipe were teammates at ferrari they were pretty even if u look at both seasons. So would it be an improvement over Massa?
I don't see Grosjean as a talent, i think he has had plenty of chances and is not F1 material. There are better guys knocking on the door. The likes of Bianchi, Magnussen, Da Costa, Frijns and Carlos Sainz, heck i even think Pic is better.
As for your Massa comment i think u are spot on, actually i think it's the same way with Grosjean at Renault..