The Age/SMH cryptic by DH #20,723

I didn't get a chance to look at this one until around 2pm. I was all over town running errands and getting a tyre fixed on my car. Damned screws in the street. I got off to a great start though and had most of the top half done in excellent time. The bottom half took me longer with clues like 16A, 26A causing me grief and then I put the wrong word in for 22D which messed up 25A. 25A once fixed and with all its letters and with help from friends on Twitter, it still wasn't working for me so I cheated on that one. I don't like the clue. We're not friends me and that clue. However I am very good friends with 4A. I liked that clue a lot. I don't see that kind of clue often enough and I was well chuffed to have figured it out.

A few questions:

14A - Call silver worker a shrew? (9)

"A shrew" is the definition and I solved this backwards as I knew a "worker" was an ANT and "silver" = AG so it was something AGANT and with the thesaurus I saw TERMAGENT but I don't know why "call" is a TERM unless it's like "What do you call that thing?" being like "what's the term for that thing?"

16A - At last! Einstein takes in some mug (5)

"Mug" is the definition and I don't know if this just a hidden word clue with "einSTEIN" or if there's more on the go. It has to be more than that but I don't see it because STEIN is shining in my face.

26A - Concerned with class level again? (7)

I think it's "concerned with" = RE and "class level"  = GRADE but how is "again" the definition for REGRADE?

There we are with the good, bad and the ugly. I did learn a new word with Rorqual which is always neat, and I got the big clues quickly. This grid only had a few clues with hanging starts (I don't know what it's called (what's the TERM for?) when the first letter has no connecting clue like 9D or 28A) so overall I'm content.