If you like having a nether, don't use buildcraft pumps. Use the gregtech advanced pump. I obliterated a mystraft lava world using BC pumps. I encountered multiple chunk resets (each time taking out the chunk with the pump) and eventually had to delete the world and allow it to fully reset (which I hate doing because it feels cheaty to me). My old pumping station consisted of two magmatic engines, a bc pump, a liquid tesseract and a chickenchunks chunkloader. My new pumping station consists of two thermal generators, an advanced pump, a liquid tesseract and a chickenchunks chunkloader and I have not had any issues with it at all.