I just wanted to report what I believe were bugs with the Multitool. Recently I was editing a save from the Conquests expansion (I haven't checked to see if it happens with the original or PTW yet) and decided that I was getting quite frustrated with the Byzantines constantly sending their Dromons into my territory. So using the SaveGame Editor I deleted every Dromon I could find (as well as any units on them to avoid possible errors.) Once I reloaded the game, however, there they were, still floating outside my borders and moving around when their turn came. When I reentered the editor, I found that according to it they were still deleted, so I tried reloading the save again and there they were.
Another problem I've had, which I believe I've seen posted here but just in case, is that I decided I wanted to get rid of these Dromons without sparking war (I had a few good deals going with the Byzantines and I didn't want to wreck them.) So I tried to create a Privateer to use for that purpose. I created two units at that time, a settler and then the Privateer. After trying to load the game I got an error and decided to check the editor again, where upon I discovered my Privateer had become a Barbarian Settler with the number assignment "0," even though it was at the bottom and there was, of course, already a "0" at the very top.
In line with that, one time I was constantly getting errors with my units and went into the editor to see that a number of units had turned into the Barbarian Settlers, all assigned to "0." Originally there were over 1000 units in the game, but now it ended at 400-something, followed by a long list of those Barbarian settlers, that seemingly never shrunk when I deleted them. However, I am unsure if that had anything to do with the editor. As far as I can tell right now it may be unrelated.
Other than that it's been working very well for me. Thanks for this great program!