So, MG, IMO, you're really, really close to nailing it here, son....as always, thanks for sharing your thoughts!
While not normally one to split hairs (daily conditioner use helps), for lack of anything better to do on this thread until the 19th, I'll just say my trail of thought is very similar to yours, but yours is like a mirror image of mine. Inverted.
Flip the clauses in your 2 sentences above, and it pretty much reflects my thinking:
He didn't want to pay child support, so he wanted sole (or whatever would be least costly to him) custody arrangements.
I keep coming back to this having something to do with finances, and part of that was the child.
IMO, the motive was driven solely by PF's needs and wants, along w/ his self-consumed ego.
PF is a cold, narcissistic little *****.
PF cares about PF, not Baby K....as evidenced by the fact that he murdered (IMO) Baby's K's loving mother, upon whom Baby K was dependent to meet her physical, emotional and developmental needs. That attachment was critical for Baby K. PF irrevocably severed that mother-child bond.
Like I said, it's really a distinction without a difference, because motive doesn't matter here. Whatever stupid reason PF manufactured in his hoof-addled brain for his evil deed, the end result is the same.
KB is dead.
All of the above: JMO.
O/T: Good luck to your team in the SB today, MG! We all know you're a huge fan!