Hmm. what do you mean by 'remove pieces of land'? is that something in reference to the actual process of map-creation, or something you want to be able to do once its finished? or are you referring to things like layers? just in case, what programme are you using?
When you say styles of world map, do mean things like projection, or faux-sepia, or gaudy fantasy 'gah-im-gonna-blind-myself-with-bright-colours' or something else?