As I recall, the answer to this is no. Only digital channels can be used.
As for the amount of memory required for the dinal sampling, the input is compressed (RLL encoded?) so if there’s not a lot of toggles, you can sample an impressive amount of data. I’ve streamed a couple of 250MHz analog data channels directly to the NVMe of my laptop for post-sample analysis.
As for the analog speed, there is an analog input anti-aliasing filter that scales with the sampling frequency that you might want to be aware of.
@BitBob did a fairly detailed analysis of it together with Tim Reyes and Mark Garrison. You can find the thread here: Saleae Logic2 Analog filtering technical details?