Re: Changing "Welcome" Message
On a new installation that is just some content created automatically on the home page, its just an instance of the Html Content feature that has been added to the page by default. The word Welcome is not coming from a resource file or config file and is not a skinning issue at all.
To change it click the gear icon next to the word Welcome to get to the feature instance settings, then click the General tab and you will see where you can change the title of the Feature Instance from Welcome to whatever you like.
Steve