3) Chris Cooper
Yes, eagle-eyed readers, Chris Cooper did already play Norman Osborn in The Amazing Spider-Man 2. In that respect, it would be strange for him to reprise the role in the MCU. After all, they don’t seem to be carrying anyone else over from that abandoned franchise.
However, Cooper should be the exception to the rule, as he was so dreadfully underused in TASM 2. Sony cast the talented actor for the sake of a few scenes where he laid in bed, coughed a bit and spouted some nonsensical exposition to Dane DaHaan’s Harry. He probably would have had a larger role in future films, but those obviously won’t happen now.
No one would surely complain, then, if Cooper played an alternate version Norman Osborn in the MCU. In fact, most probably wouldn’t even know he had already played him.