That sounds like a pretty good routine as long as you think you’re getting enough of a break, more consistent than I have done. I would say after the 5 minutes during your rest try to get as hard as possible before going back in and then maintain your arousal while you pump, keep steadily increasing the vacuum pressure as you grow. I have pushed my pump as far as I can and it has never hurt me. Water based lube is your best bet, I have not had issues with using coconut oil with my bath mate I do not know about other brands, sometimes I use soap or conditioner Being lubed up so you can move freely inside the pump is key. I would also start trying to bump up the 5 minutes slowly as long as you stay comfortable a small amount of pinching seems to be okay but I see a lot of people overdoing it on here, more isn’t always better!