Could you link to the source material by Mage Kiing or repost it. You seem to refer to it a lot in the quasi-template and it is difficult to judge without it.
I have it saved to my hard-drive. I'll try and see if I can find a link to where he originally posted it before resorting to pasting it here.

Since your Heartless have the same features as Undead why are they just not a Subtype of Undead like Dealthless? It makes sense they'd have a new Subtype since their Traits are different.
I'm...pretty certain Deathless are their own Type entirely? And they don't have the same features? Different hit die, BAB advancement, they lack INT but have CON...

You should use standard terminology when possible. Immunity to critical hits (not precision damage for example) and you should note the differences between standard undead traits and heartless traits a bit more clearly. See Deathless from Book of Exalted Deeds for example.
Noted.

It looks like your template and traits run together. I know it's a pain to repeat information but that's exactly what you should do. The Template needs some expansion.
That's a bit of an issue i'm having; it's unusual for a type to give special qualities and such like I want to give them, so the Heartless bit is just laid out like a template without being one per se. I'm not sure how to write it elegantly.

The Nobody type and the Humanoid Nobody template are distinct though.

Limit break should round DOWN.
Whoops, didn't even notice! I'll fix it. Thanks!