I think Sundance is suspicious of Malkin’s long-term goals. Rightly so, in my opinion. I think he explained that quite well in the referenced article.
As far as Levin threatening to reveal who “Sundance” is... oooooo, scary. A simple google search will give you the info. Levin sounded like a thug in his tweet.
Sundance was absolutely the best blog during the election. I had to go there many times daily to maintain my sanity.
Sundance was very good during this election cycle. Malkin has been very good on the issues that I like most about Trump for the last 20 years, so I have no intention of throwing her under the bus. Levin, otoh....