Sebastien,
I think I cannot provide the second and the third question, for it is illegal using Google Map. A logo is a way for the owner of copyrighted material to publicize ownership as well as the provider information. Please see the following for the rest two questions.
1, the coordinates can be disabled by the following code; you can directly remove the code for it is false by default.
Map1.MapTools.ScaleLine.Enabled = fasle;
4, customize the scale line is a little complicate.
4.1, If your requirement is not too complicated, please go to [Application Path]\Theme\Default\Style.css, you can find the definition of .olControlScaleLine, .olControlsScaleLineBottom and .olControlScaleLineTop which maintains the style of the current scale line.
4.2, If the style of the scale line cannot satisfy you, you can rewrite the scale line of OpenLayers.
Please let me know if you have any questions.
Thanks,
Howard