Yes but to come back after Rallying (crashing) will also be a huge challenge. Regardless of it being a year out or three, the cars change dramatically year in year out, and I just see Kubica taking him to pieces like Massa did from mid 08 to his head injury in mid 09.
stop talking about motivation and formula one ^^talk about money
More seriously, although Raïkkonen was the best driver of formula one (only few errors of driving (I mean lock up, ...), so many fastest lap in races) but I think he isn't done for formula one and his world. He isn't interested in it.
Moreover Sutil is one of the best driver of formula one and maybe the best when it rains so...
Frankly, all the drivers in your list would be nuts not to talk to Renault about a drive for next season, unless they're already signed (in the case of Timo Glock).
Since the Departure of Honda, Toyota and BMW being in a Factory team is a much Bigger privilege then it once was, thats why Teams like Williams are desperate to get a Factory deal going.