Whatever Russia's actions, blaming them for Clinton's loss is a losing battle.
Absolutely. The Democratic party needs to either talk about the issues that actually effect people, or die.
I fully expect Democrats to attack Trump "from the right" on foreign policy in 2020.
I'd be very surprised if that happened. Clinton was much more hawkish than most Democrats, and they're likely going to try and move away from Clintonism.
That would be the sane thing to do, but this is US politics we're talking about.