Twenty Fourteen Questions

I kinda like the new Twenty Fourteen theme but I would like to change it a little but can’t seem to figure out how, here’s what I would like to change.

I would like it to be centered and not to the left which it currently is.
I want my 2 menus along the top of the site as we see in many other themes and not shoved to the left of the site.

I also want to know how I can get the featured image slider to show 5 or so posts from a particular category rather than just looking for the tag “featured”.