1.) I wouldn't go messing about with your save file without saving it first because thats a good way to screw it up and lose your game. That goes for pretty much any file you mess with in OXCE, but especially save games. And some of those variables for the Kitsune in the save I am willing to bet are tied to the research aspect given its seemingly unique nature.
2.) yes you could do it. I know its possible in theory to change what craft are in your hangar via the saves if you know enough about what to change and what to change it to. I kinda know through trial and error, but I'm not sure I could simply explain it so it would work for you over the internet, nor do I know what your skill level is in editing such files, so either my explanation or something you dont know could cause it not to work.
Beyond that its only something I did temporarily (partly to see if it would work, and mostly when messing around during my own modding experiments) and I never used it on a permanent save and I've only used it with vehicles easily purchased (EG no unusual or unique craft) so I dont know if doing that would have unintended consequences (some changes you can make to OXCE files including save files may require changes be made elsewhere, and unless you know what to change it means that - at best - what you try doesn't work. At worst, it can mean it's an error that will crash your game.)
And I've done enough modding so far to know that sometimes errors don't happen right away (I've been playing around with creating new weapons for my own game for example, and I've had the game run fine until it runs into an error I made and then crash, later.) That sort of thing can increase the chances of you losing your save, plus any progress you make up to that point.
The safest/easist thing might be to revert to a save when it was destroyed.
