Here are two videos by Gulenko where he explains it. I hope it helps


How to date a dual:



About duality as a relational principle:




About the other question, you can still love whom you like, duality is just a benchmark and not an absolute must. I have an inclination toward IEI/SEE/ILI as well, not just SLI.

Believing is probably not the right word, it's rather taking it as a perspective to look at life or not. Socionics = a theoretical angle.