I don't really see where you're coming from with the off-putting personality thing.

Warren can't really connect with voters outside of coastal and solid Democratic states. She has the kind of personalty where you'll either love her or hate her. Her personality is very headmistressy to say the least. She also comes off as very shrill. These aren't qualities that will appeal to the average voter in swing states.

I feel like a middle of road candidate will be viewed by a large majority of the part as Hillary 2.0.

Hillary didn't lose the election because she was too middle of the road. If you had run Julian Castro, Deval Patrick, or Terry McAulliffee this election, Trump would have lost by double digits. Centrism isn't a problem as long as you don't run an Al Gore or John Kerry like candidate.

She's an impassioned progressive who's willing to put her money where her mouth is

Liberal stalwarts Russ Feingold and Ted Strickland both lost by bigger margins then Hillary Clinton. Feingold had the record to back up his promises as well. Being a progressive won't be enough to win an election. Ohio and Wisconsin both rejected very progressive candidates.