I only ever delete the localthumbcache.package before I play. As far as deleting your game saves, just be aware that while you may remove them from the menu inside the game, that doesn't remove them from your document file. There is a small tab on the lower corner of the game set to load. Hover over that and it will give you the number of that file. This will enable you to know which file to remove from your documents file, as well. And for will it hurt your game to remove older saves, not at all. I have been known to go on a full-blown cleaning and rid said file of everything! I don't like clutter. But, that means I just have to start my families anew.