Fussing over a new cartridge installation

I have just installed an Ortofon Super OM20 on my Harmon Kardon T-45 turntable, and am enjoying LP's with an enthusiasm I haven't in twenty years. I have a couple of setup questions, though.
1. The H-K table has a "Capacitance trim" setting. I have found a capacitance listing for the cart, but no such info for the amp (an NAD AV713 reciever). Any advice about this?
2. After setting up the cart (which is an immediate and dramatic improvement on the worn old Grado that preceeded it), I learned that the Ortofon cart has a removable weight. The H-K "Microrace by Ito" tonearm is relatively light weight--would there be any significant benefit to re-installing the cart without the weight?
3. I bought the turntable second hand a few years ago, and the previous owner included a second headshell, from Audio Technica, which appeared unused. I found that the gold contacts on the H-K headshell were too small to fit the prongs on the ortofon cart, so I mounted it in the A-T (non-gold) headshell. It seems fine, but I'm just mentioning this in case there is some advantage to the original headshell or wiring that I should know about.

Thanks in advance for your reply.