AIP Australia lists "P" as pah - PAH, indicating a stress on the second syllable. That's how most of us pronounce it over here.
Personally tend to stick to the books on the use of language - mainly to be standard especially when it comes to international pilots. Nin-er, Fife, keh-beck etc. I think most who choose to deviate (e.g. Fox for Foxtrot) probably do it because they think it sounds cooler ... not really a time issue here!
But I stop short at "tree" - frequency transfers in our neck of the woods become more of a toungue twister if you do that. But like LateLandingClearance, we have the one who uses "tree".