1. Prices will increase
if we get rid of the penny, store owners, and merchants will have to round UP to the nickel, forcing the buyer to pay MORE! And trust me it all adds up.
LOL, I disagree with all of the reasons you gave. For one thing, I think it would take a hell of a long time for the rounding-up effect to get to a point where it would affect the average person. I'd be willing to do it. Plus Canada has already gotten rid of their penny, and I don't think it's thrown them into any sort of crisis.
The penny just isn't worth what it used to be, and charities can start taking nickels if that's what they asked for, and I'm sure they'd get them too. Having the government mint a bunch of coins that never get used and which cost more to mint than their face value is absurd, and none of the reasons you gave justify it.
I've been saving pre-'82 pennies for some time now, just as a weird sort of hobby. I'm sure you all know why, even if it's currently illegal to melt them. They just don't make them like they used to.