Thanks for the feedback! I added a small comment on "Sources directly related to the subject". Basically, the idea behind this is that it's very easy for someone to be subjective about themselves when making a personal web site. But you're right, things like pronouns (and language in general) and confirming quotes is ok.
As for YouTube, that's why it's in the acceptable column, together with social networks. Social networks are a very grey area, that's why they are in orange. It's a way of telling people "think before using this as a reference". A reputable channel is a good source, just like how the gender census tumblr blog is probably one of the most used sources on this wiki. It's a matter of context, I guess. I've also added a clarification note under the table.
Let me know what you think about the changes!