IMO, the most important limit to socionics one can learn...
where socionics ends,
An important limit to socionics I think, besides the obvious language and cultural barriers, is personal values. How we think of certain groups of people, and our politics, I think this goes beyond socionics. For example, my grandmother is my identical. However, she doesn't really have the same political ideals as I do, and also doesn't advocate for the same groups of people that I do. It's kind of a bitch, because on an innate psychological level we get along so well. I can rant to her about my emotional states a lot better than I can to my alpha parents, it's just so better well received. However, there is that proverbial brick wall that comes up. Our different life experiences and being raised in different external circumstances and other non-socionic psychological factors, just caused us to have different beliefs that are hard to settle with each other. It's not ALL different. We're both liberals, but that's about it.