Do you risk ruining the whole relationship (because people generally freak out when the word "herpes" in involved) over a nearly negligible risk?

Yes. You explain your situation, educate the person about the negligible risk, and then allow him/her to make the call.

If I were involved with someone, and found out that s/he'd withheld this information from me, it would be over instantly. Other people don't get to manage my STI exposure through silence and lies.