Bunch of Questions

I love this theme, but there are a few things I’d like to change.

First, is it possible to change the header and footer colours independent of each other? It seems like the customization option overrides anything in style.css.

Also how can I remove the two lines at the bottom of each post? As well as the lines beneath “continue reading” on the blog homepage? I don’t see these anywhere in style.css.

Also is it possible to change the text in the footer? I have no idea how to find the source code for that.

Lastly is it possible to add a search form either in the top navigation section or beside the site logo? I know this is probably a bit tricky.

Thanks for any help!