For Mr. Petersen, the questions in general should have been elementary. The fact he did not know them is actually quite deplorable. To your questions specifically:
Should Mr. Petersen, as a Juris Doctor, know of those things in his sleep?
This is the wrong question. The question is: should an individual who has accepted a nomination to serve as a federal judge on the U.S. District Court know of those things in his/her sleep? The answer is unequivocally yes. One could almost argue - one would likely be scoffed at, but one could - that an appointment to a higher court, the U.S. Circuit, could get away not knowing those things 'in his/her sleep,' because appeals courts would not deal with, e.g., abstention doctrines or whether to admit expert scientific testimony, as often as a trial court does.
Simply put, lawyers should at least have heard of those things (he looked/sounded absolutely dumbfounded at the words that were being said to him), litigators should know them, and federal trial court judges absolutely need to know those things to do the job.
Is his excuse valid when he says that he has no background in the
field(s) (he mentioned litigation once) the terms are corresponding
If he was just some lawyer talking to some guy at a bar, sure, totally valid. If someone is a corporate M&A or project finance attorney, sure, don't expect him to win any trial court vocabulary contests. However, when sitting before a panel of U.S. Senators carrying out their Constitutional duties of "advice and consent" on presidential appointments, not knowing those things can, should, and indeed did end in complete humiliation for the person ignorant enough to try and go through with that. I'm sure his hearing was scheduled some time in advance. The fact he obviously made zero attempt to know anything is actually insulting to everyone involved.
For context, I wrote a motion in limine at my first internship. If I live to be 1,000 and never step foot in a court room, I'll still be able to say more about a motion in limine than "I would probably not be able to give you a good definition right here at the table."