OK, not going to parody the song any more than that. Well, maybe later...
What I'm curious about is playing members of the dedicated Legions - the World Eaters, Emperor's Children, Thousand Sons, and Death Guard.
I've read that not every member of the Emperor's Children has the Mark of Slaanesh (although that is the only mark they can get) and most of them are not Noise Marines. Seems fine for making all manner of CSM starting characters.
Now with the World Eaters and the Death Guard I'm a little less clear. Is every member of the World Eaters a Berserker with the Mark of Khorne? Is every member fo the Death Guard a Plague Marine with the Mark of Nurgle? If these are the only options within these Legions, that really pushes belonging to them out of the realm of starting PCs.
With the Thousand Sons, Sorcerers are obvious and easy, but shouldn't they all have the Mark of Tzeentch (the Rubric of Ahriman somehow enhanced their powers, so it could be this and/or Warpsmith or simply always counting as Aligned to Tzeentch)? But what about non-sorcerers of the Thousand Sons? Is the Rubric of Ahriman still converting non-psykers implanted with Thousand Sons gene-seed (harvested from Sorcerers post-Rubric) to dust, or is it simply that the Sorcerers just don't/can't recruit non-psykers?