Are the following sentences correct please?

Are the following few sentences correctly written please?

Walk in the direction in which you see something other than mountains.

I am (standing) where you left me 10 minutes ago. (Is standing optional?)

Someone who works (for a living) as opposed someone who mooches people is more respectable no matter their profession. (Is for a living redundant)
What wouldn't/would she say to get what she want.

The book is based on/about how they got to america during world war 2.

Which are correct please?

How/Why do you know how to speak Spanish?

How come you know how to/can speak Spanish?

Why is it that you know how to/can speak Spanish?

Thank you and happy new year!