Well, why would talking to Impa be a bad idea? I don't know how useful that is, but getting back to Kakariko isn't time-consuming (unless you're going by foot).
You can do the Divine Beast quests in any order. The order I went was Zora's Domain-> Goron City-> Gerudo Town-> Rito Village. It seems like most people think Rito Village and Zora's Domain are good ones to start with.