Removing Parallax & Responsive Image – 2 Questions

I’m looking to remove the parallax function on this home page (scroll down to “One Tank Dive”)

And THEN…dun dun dun…

I’d like to make sure the banner image found on the other pages (see the About Us page, for example) is fully responsive to the size of the screen, which it’s not.

I’m sure, like all of my other questions, these have simple answers. But I’m on a crunch and don’t have time to fiddle. So teach me, fellow jedi peeps, and I’ll be a good padawan.