2013Dad - Your scenario wouldn't have happened in our house for reasons I've already outlined. In both cases, there were schools our sons would have committed to early (and did) and others they would have asked to wait (and did) until they had more information. Some schools let them wait for more information, some did not. I'm ok with that.
With son #2 we did in fact run-to-ground the other school or two he thought he might(?) have more interest in (his own "UM's"). We talked directly with those coaches and got a full, honest and upfront assessment of where he stood with them (which fell in the category of maybe...even probably...but not a 'sure thing' yet). With that information, he settled on his choice, made his commitment, informed the other coaches on what he had done...and aside one who tried a late shot a finding out if he had a 'change of heart'...that was it.
But yes, I have a far bigger problem with families that continue to 'shop' after making a commitment than in the scenario you describe. However, I would still strongly advise (if nothing more than for the good example I believe you'll clearly show your son)...that you openly discuss your dilemna with the D2 coach as ClevelandDad's son did with the D3 coach.
And yes, if none of it works out...college without baseball should be an option you consider strongly. My sons could have (and would have) done it if that were in their best interests.