For example I'm going to use hashtables for each entity, if a number of entities gets into hundreds, I imagine simply saving hashtables would result in hundreds of small files. Not good. So I was thinking I could dump them into the ZIP.
On another thought, I guess there is no point of removing a specific file at all if I'm just using this to save and load the game. Either load all or don't load at all. Dynamic file structure - such as some sort of database - would probably be better off with something other than the ZIP due to the performance hit.
Edit: Funny thing, I was experiencing a crash on closing the application until I removed the ZIP object. All I could get was runtime error popup, which disappeared too quickly.