Wouldn't it be easier to translate "No tenía más que unas monedas en el bolsillo." to "He didn't have more than a few coins in his pocket." rather than "He only had a few coins in his pocket."? This type of translation would work for the "más que +noun" instances.
Can "No tienes más que decirlo y yo estaré allí para ayudarte." be translated to "You don't have to say anything more than it/that and I will be there to help you." rather than "You just have to say it and I will be there to help you."?