Is there a feature that allows you to replay all of your missed tactics trainer problems in a row without having to individually click on them?  I'm envisioning a process similar to studying with flash cards where you keep the ones you missed in a separate pile and continue going over them (however many times are necessary) until you haven't missed any.

I'd kill for this feature.  Given that the buffer of previously done tactics is limited, I literally copy the "failed" positions into my personal DB. 

Agree completely. We know that the repetition is the base of learning, and it would be great if we can see more of previous problems tried. Now it is limited too much.