I have recently purchased a mature plant of Paph. Chou-Yi Rookie (thaianum ' Pearl' x rothschildianum ' Rex' FCC/AOS). I am puzzled with the amount of light to grow it in. Should I grow it in lower light because of the Brachypetalum influence or in brighter light with my other multiflora Paphs.? Thank you in advance for any help that you can provide.

It is more then likely that the Rothschildianum parent will dominate both in flower size and shape. If it didn't why make these hybrids at all?
These are likely to mature as smaller plants compared to a Roth. I would say if Roth's like some sun, maybe 4-5 hours of very good light, I would try these with 2-3 hours of real good light.
Let the leaf color tell you. If the leaves go real yellow green, back off on the light a bit. If they grow with a very dark green leaf color, give them more light.
React according to what you see.