Pangs Of Conscience

If the generation of Noach were wicked and did not repent because they laughed off his warnings, why would they wish to stop him from entering the ark if the whole thing was just a hoax in their minds?  The Midrash and Gemarah says that the people in the generation of the flood did not steal outright but rather every individual stole less than a perutah so that they could not be held culpable in court.  If they did not care about having morals, why not just steal outright?  We see that even though the generation was not righteous, they had a guilty conscience.  They didn't just openly steal for they would have felt bad doing so.  Therefore, they only stole an amount that can't be prosecuted which they could justify to themselves.  That is why they felt the need to stop Noach from entering the ark for they knew in their hearts that his prediction was true.  Their conscience knew the truth even if they wouldn't admit it outwardly (Pneneyeh Daat.)  

On the one hand this demonstrates man's inability to do the right thing despite the pains of conscience but on the other hand it means there is a place to start from which the person can get better. 

Why was the rainbow chosen as the sign of the peace treaty of Hashem?  Rav Solevetchik explains that Hashem was teaching Noach.  You couldn't convince the people to do teshuva because you did not believe in them.  You believed they were rotten through and through and could not improve.  (To get someone to repent, you must believe they can.)  You only saw the dark clouds of their behavior.  You did not see how the pains of conscience are a small drop of water that when exposed to the proper light can turn into a bright rainbow (see here and here.)  

Rashi says the mabul was delayed for seven days to allow for time for the eulogy of Meshushelach.  Why is that a reason to delay the flood?  I think the point may be that the hope was the inspiration from hearing the eulogy of such a great man would inspire them to do teshuva.  It was a last hurrah to give the ability to turn things around.  Rav Elyashiv credited some of his greatness to being inspired in his youth from hespidim given for the Ostrovska gaon. 

Rav Leeb Gorvitz says along the lines of the previous idea.  If they are giving hespedim for the loss of Meshushelach, it means the people feel a connection, albeit remote, to Meshushelach's way of life and that connection is reason to delay the flood.