Don't even mess with the BPV bs, just get an aftermarket BOV and relocate the MAF sensor. I have a 7" tall FMIC core without cutting the bumper or crash bar, it will fit fine.
What for? I don't know why they are there but I also don't know why it matters? lol
Inconsistent boost could be an ignition issue, internal wastegate flapper backed out of exhaust housing, boost/vac leak, failing turbo, etc, several things could cause it.
Do you still use the stock T-fitting for the vacuum lines for the wastegate actuator and bypass valve? A strong, independent vacuum source for your WGA and BPV may help a little bit. At the very least, it will eliminate one of the possibilities.
You should look into replacing all the original vac lines with silicone.