The personality type I most identify with is INTP ("The Thinker" or "The Architect"), but every time I take a personality test I get a different answer (as you can see on my tests page here). I am always a strong T (more analytical than emotional), but apparently I'm near the middle on the other three axes. Or maybe they're just not very good tests!
I consider myself polyamorous, in that I am comfortable dating people who are also in other relationships. I haven't been in multiple simultaneous relationships much myself, but I think I would be comfortable with that too. On the other hand, I have also been confortable in monogamous relationships, and would be comfortable in a monogamous relationship with the right person. So I don't think this should be a dealbreaker in either direction. But it's hard to get that across in the Questions here.
Speaking of Questions, I enjoy looking at match percentages and seeing where we differ, but I try not to take them too seriously. I'm open-minded, and while it is important to have things in common, I don't think a relationship needs to be about maximizing similarity. Mainly I'm looking for mutual attraction and compatible personalities. The rest will follow, right?