I did not say religious level-YO said that. There is a big difference between that and affiliation. Perhaps “societal religious affiliation” would be more accurate.
We all choose how we want to dress and that choice is a reflection of how we want others to view us and with whom we want to afilaite. Someone who wears ripped jeans and a t-shirt is making a statement that he would like to affiliate with a certain segment of society and someone who regularly wears a suit and tie also makes a statement. It is the same with yarlmukas. If a person wears a white kippa seruga he makes a statement and if he wears a big or small one he is also making a statement as to how he would like to be classified. These are self classifications. If you wear the yarlmuka of gerrer chasidim or those of Toldos Aharon chasidim that is also a statement.
I agree that anyone who would try to judge a person closeness to G-d, his level of Torah knowledge or yirat shomayim by looking at his kippa is and idiot bec. he thinks HE is G-d (i.e. only G-d really knows this stuff).
It all goes back to the same principle of the OP- we choose to affiliate and label ourselves with the group that WE choose. If a Livak wakes up one day and decides to become a Chabad chosid that will be his decision on which society he would like to affiliate. Hopefully most people decide to label themselves based on the path in avodos Hashem that he feels he can best accomplish his own personal mission in life and achieve his greatest potential.