Ok, so I found the answer to my question re: high beam/flasher:
The flasher is just that - a flasher not high-beam mode.
The Bi-xenons have a lid that covers it in low-beam mode. When you actually engage the high-beam mode the lid retracts - that is why its called bi-xenon.
Still trying to figure out if I have to remove the bumper to change the ballast....