New to this site, following the thread since day 1...
It seems it would be a huge leap to think that either Holly or her brother were involved in her disappearance; all personality and lifestyle evidence suggest that would not fit her profile.
My fear is that LE was simply not initially prepared for extent of premeditation involved in this abduction...
It is difficult for me to imagine that, by this point, LE/TBI do not have significant leads on a culprit. It appears most likely that Holly's abductor was known to her (or knew her). In such a small (and seemingly tight-knit) community, one would think it impossible for someone's absence or abnormal behaviour to go unnoticed.
(As a sidenote, thank you to all posters that have been updating this thread since Holly's disappearance)