1) that actually seems like a pretty smart solution
2) I don't think having your e-mails illegally leaked out counts as a 'shortcoming' unless you're referring to their poor choice in data security
It's unacceptable for information, especially classified information or otherwise sensitive data, to be able to be accessed by foreign actors, period.
This information is obtained through the incompetence of those handling it. In other words, while the leaks may have been obtained by "hackers," there is at least a portion of liability on the Clinton Campaign/State Department for handling information in a way which was both negligent and unsecured. It would have been exponentially more difficult to obtain such information had it been properly encrypted and transmitted through secure channels. It wasn't, and that's the only reason this is a problem in the first place.
I will say, however, that this is a situation of love the leak, hate the leaker.
I'm glad corruption is being exposed, but if it truly is Russia behind this, which it is too early to tell, I would be upset about the level of growing Russian influence.