If I install a different launcher on Android will the UI of everything be different?

I'm planning on buying a sony ericcson xperia x10 mini pro but I don't like the blueish UI I saw video of it running ADW Launcher and that looked great but,

Does using a开发者_C百科 different launcher also change the UI in the texting/emailing screens? , I want to have homescreens like ADW Launcher and the texting/emailing UI should look like pure android or ADW style.

When I think about the word "launcher" it isn't clear, does it modify only the home screens or the entire UI of the android operating system

Installing a new home launcher will only modify things it has control over, i.e. the home screens themselves. The UI remains the same in every other app, menu, etc. You can also just uninstall the app (ADW) if you don't like it.

And as far as the Xperia you're talking about, I know for most skins (Sense, Touchwiz, etc) there's no easy way to disable them. You'll probably have to wait for it to be rooted, and then install a stock ROM of Froyo on it.