Blasphemy

A person who very prominently displays religious symbols (such as a large kippah, shaved head, long wigs, long beard, etc.) and appears very strange to most of the world, is this blasphemy?

I don't think so. It's like we wouldn't consider it blasphemy to adhere to the laws of Shabbat even though it seems strange to people. Although in a place where the strangeness is also in a religious context, then maybe it is (like the women of the Shalem).

If it is something that is not obligatory, why wouldn't it be considered blasphemy? (Regarding the examples I mentioned, I'm not sure they have any halakhic significance at all.)

The world understands that these are religious symbols. There may be a situation where this would be blasphemy. Each situation is unique.

It's clear that people understand that these are religious symbols, but that certainly doesn't bring them closer because they don't want to seem strange.