A student of handwriting analysis writes in about David Gest's freakish signature. NYU's Andy Bellatti kicks the hard science thusly:

Firstly, your handwriting reveals how you are as a person, while your signature represents how you come across in public. His signature is pretty fucked up, you are right. In it, his upper zone is REALLY pronounced (as witnessed by those lovely wisps that go HALFWAY UP THE PAGE!). This points at someone who in public likes to come across as overly idealistic, loopy, or with their head in the clouds. It also means he is aware of his weird public persona and in many ways, consciously makes it even more grandiose and bizarre. In his signature, the way the 'i' is dotted shows someone who is very nostalgic/stuck in the past.