Couple things to consider:
First regarding the bats, since the NCAA implemented the BBCOR bats last year the home runs dropped nearly 50%. That is a huge number. So the bats aren't nearly as hot as they used to be and hit a lot more like wood, not saying exactly but a lot closer. Main difference being you don't snap it if you hit it under the label. Also keep in mind the $$ involved with these bats. The manufacturers use the college teams to market these bats to the high schoolers and little leagues accross the country. The bat companies I'm sure have their hand in it some way or another, whether giving $$ to the NCAA or something. They don't want to go to wood because they can't market the wood to the younger kids unless all the high schools and little leagues go to wood. When seeing a CWS team using a model of metal, the sales skyrocket. Rawlings never hardly sold a metal bat until S. Carolina used them and won it, now they have sold a ton of that model.
About the schedule, one thing to keep in mind is the MLB draft is early June. They want these guys in their system right after the draft. If the colleges played summer ball, the kids would either A) have to leave school to sign or B) have to wait all the way till the following year to play pro ball. The MLB teams won't go for this, no way they want their future investment playing college ball and risking injury. It is the same reason you see Iowa High School players that have gotten drafted high not play their Senior Season of High School, because their agent won't let them so they don't risk injury before signing and also the team that drafted them wants them in the minors asap if they are paying them.
Just not really a perfect system. About the only thing I can think of is changing the MLB draft to postseason like all the other sports. I don't believe any other major sports have their draft during the middle of their actual season. Change the MLB draft to November, then have them signed and ready by spring training???
Just my two cents.