No wonder Hirani's first choice has always been Shahrukh......and silly Shahrukh refused some of the most iconic roles....but those movies were done by other amazing actors who owned those movies.....hopefully Shahrukh backed by Hirani will own Dunki...Fingers and toes all crossed...
Just the premise which has to do with the meaning of the title
I don't think that SRK "refused" them...he had - at least in his eyes - valuable reasons to ask Hirani to look for another actor.
Hirani himself told that when he approached SRK for the first time (for Munnabhai), latter was about to get back surgery. As SRK did not know how the outcome would be (paralysis was a looming danger), he asked Hirani to better look for another actor (and later acknowledged Hiranis choice of Sanjay as a perfect one - and rightly so).
I don't know the exact reasons for 3 Idiots (dates problems are cited) but maybe SRK didn't feel comfortable with the role (neither did I with Aamir when watching the movie).
Did Hirani offer the PK role to SRK??? No idea. I disliked Aamir's eyes-wide-open performance...(the reason why I'll never watch his version of Forrest Gump)