I'm assuming here that an unhealthy person would either be emotionally in turmoil and / or not communicating well. I'm unsure of how else to define "unhealthy." It may be difficult to start relationships of any kind in this circumstance.

However, if you are with a dual that is genuinely interested in you, they'll notice. Whether or not they say they notice may depend on type. But from personal experience (Ne here), my dual knew when I was unwell emotionally. He didn't always speak about it or want to talk about it, but he knew and it upset him.

As for conflict vs dual... I've found that humor and clothing styles are a good way to narrow things down, but it takes time. And by the way, it's possible to really enjoy conflictors. "Liking vs not liking" isn't a valid way to narrow down. I think much of it boils down to how information is processed, communicated, and decoded. I get along extremely well with my conflictor sister in law. On the surface she seems very similar to my SLI hubby, but I think with enough time together, and especially if we were constantly in intimate settings where hearts are deeply involved, we might find each other encoding and decoding our communications differently. She would also probably be annoyed at some of my IEE quirks and may not feel like I was bringing something of value to her in a relationship specifically, and vice versa. But I'm able to enjoy her for who she is because I'm not looking to her emotionally in that way. her humor is also the funniest in the whole family, I think!