School child's pride and Sailor's guide. What am I?

While I held the warp and she did the weaving of the west, a tall shadowy figure stood over her. Change my first to a z and it is something on which many who wfh spend too much time. Change my first to vr and make me twins for the sound a child’s race car makes.

I wear a crown but rule no land, I blush in red or dress in green, Doctors praise me with a plan, Yet I’m often bitten, rarely seen. What am I?

No, I don’t want a stinkin’ cracker. And why would you assume my name is Polly? I bet someone punched out one of your eyes because of the way you Aaaaarrrrr

A powder room they'd seek, A place to freshen up and take a peek. A private chamber, quiet and snug, Where nature calls, you'll feel quite smug.