Penchant/WMG

Macey is the Robo-Rasper

 * She's been calling Andrew to warn him while possessed by the Slender Man.

The blog is run by only one person

 * Meta guess here, but the writing style of Macey, Andrew, and Tyler seems very similar. I presume one person may be behind all of the posts.

A.A.F is in on the whole thing

 * He's one of the people who writes the blog commenting on another account.

Tyler is a Time Lord

 * It's Tyler TIME.