1) Her electoral performances have been anywhere from mediocre to absolutely terrible in every prominent race in which she has been the candidate. In 2010 and 2014, she underperformed the average CA statewide D margin by double-digits.
This was not remotely true in 2014. She performed significantly better than Yee and Padilla, as well as slightly better than Newsom; she only ran behind Brown and Chiang.
To be fair though, Yee and Padilla weren't incumbents.
I mean, even if we're assuming that incumbency is a huge advantage, she only ran slightly behind two incumbents and ran slightly ahead of another; that's pretty much a wash. Certainly not "underperforming by double-digits" among incumbent Democrats, let alone among all statewide Democrats (which was the initial statement).