Thanks for the advice!

As a quick update - the Bhopal Shatabdi Express Train #12002 from NDLS to AGC was quick and easy. It left on time at 6:15AM and getting to the station 10-15 minutes prior was a reasonable amount of time to navigate our way onto the train (though it would be wise to plan a bit more time in case of any issues). There was no need to pickup any tickets at the station as passports were sufficient for our e-tickets.

The return trip on Punjab Mail Train #12137 from AGC to NDLS was another story. Train was delayed 10 hours and there was no way to rebook e-tickets at the station so we ended up just purchasing another set of tickets for the next train home. Needless to say 3 1/2 hours in 2nd class (no AC) was an authentic experience.