I thought oil squirters were only for piston cooling. Crank splash onto the cylinder walls is for proper oiling/avoiding starvation, IIRC. That was the issue with the balance shafts - they blocked splash up into cylinder 3.
The GTX2867r is a 47 lbs/min turbo. This very likely won't get you close to 500whp. Consult a reputable tuner for more on this. Justin only his 445whp on his, and with head work (don't take my word on it). Found the info I referred to in the other thread:
http://www.mazdaspeedforums.org/forum/f428/gtx2867-445hp-159176/
Lex from Stratified referred to the 2867 as a 440whp turbo for most folks (without that extra engine work).