I saw that production when it was new-out a couple of years ago.  It's quite controversial - they play the anti-semitic elements of the play full-on, as it's surmised Shakespeare's audience might have seen it played.  The idea, I believe, is to bring you up short with such shockingly discriminatory behaviour, so that it makes you challenge your own thoughts on the matter.   I thought it was a successful show.

If you like all the Dr Who stuff (as per your other posting)....  the last time they performed THE MERCHANT, Antonio was played by Paul Darrow,  who played the machiavellian "Avon" in "Blake's Seven"...  "playing against type", and extemely effectively, too.  Blake's Seven actually started very promisingly,  but quickly became a parody of itself, and was a sitting target to be spoofed by Red Dwarf.   I always had a soft spot for Jacqueline Pearce as Servalan, though

Back with THE MERCHANT, it's well worth contrasting with Marlowe's THE JEW OF MALTA, which approaches a near-identical subject from the completely opposite viewpoint... a stupendous play which is too-little performed (as indeed is nearly all of Marlowe's work, although The Globe did EDWARD II two years ago).

Why do totalitarian empires always make the best earrings?

I remember seeing this at the Barbican years ago, when I was doing A Level Lit and my dissertation was about these two plays. I think it was Antony Sher playing Barabbas.

Not really sure about that. But I'm certain it's best to use only small pieces rather than trying to put a whole one on a headpin. Of course, smaller ones can be used whole for pendants.