A way I try to cut out duplicate mapped objects, like navigation links, is by having a parent page object wherein the URL consists of only the official name of the site capped with *s. I map all of m...
You can tell TestComplete to just not map automatically on recording. Under Tools | Options | Engines | NameMapping turn off the "Map object names automatically". This does not prevent you from manually mapping it just means that ALL mapping is manual. To be honest, I prefer that because it means I have more control over what gets mapped and how rather than letting TestComplete decide.