No one can rule out SD, no one at all except police, there is as much proof to suggest he is the MAE/MAP as there is to suggest he is not which was the reason for discussing him in order to find info together to rule him in or out. Saying SD was never on the police radar is insane, In most cases and especially this one, any male aged late teens and older that had anything to do with any of these girls would at the very least be a person of interest until ruled out.
I find it highly unlikely that a serial killer would post such vids to youtube in the public domain however this kind of blatant ownership of a crime isn't unheard of. for example BTK got caught because he started writing letters to the newspaper and police taunting them with pieces of jewelry, dolls in bondage and the ID of some of his victims. Its not that uncommon for a serial killer to expose himself in some way when he feels he is not getting the recognition that he deserves, even more so when a suspect with no links to the crime is getting credit for his handy work.
Does anyone have any info on Judomans employment history for around the time of the murders? I can't find any info relating too before 2004ish I was hoping to establish a link between his and SS workplaces. BSD consultants (where SS worked) have used a number of consultants in the past and some of their projects would likely include financial consultants, so being able to prove any kind of working relationship between these two would go a long way.