Help inserting images under nav bar

[AlexisMedia]

Oh, ok cool. Sorry if it was kinda obvious but somehow I just wasn't getting it.

If I edit my templates in this way then what happens at typical updates and/or at the future vB5? Will I have to redo these each time? I understand that the additional.css file will remain untouched but I'm not sure about the templates themselves?

If I wanted to remove the nav-bar all together could I just delete all the nav-bar code within that nav template and that not effect anything in the future as well?

Thanks! Just wanting to be sure I understand this before making too many edits and regretting it later...