Solution to the lips problem:
Take your dominant hand and hold your lip apart
Speak some of these
lines the arbiter says like you normally would.
As you see, your teeth can make a pretty good substitute for lips. Now that is if your teeth are just always showing... the Sangheili have 4 mandibles which they can use to block the air being forced out of the lungs to help make a more pronounced "P" "B" or "M". Everything else can do a good job with using the teeth alone.
With practice, you would be able to learn how to make a B, M, and P sound by using your tongue to block off certain passage of air.