Edit: Why not name it earth.mis since that's what runs by default when you load the game? By that I mean name it earth.mis and put it in the fan-mission folder so when you start the fan mission this thing loads straight away.
Well I just tested it and renaming alone.mis to earth.mis does allow it to run straight away, but the catch there is that I never setup the user interface (since in the level editor you have that good to go from the get go). So you'd not be able to open the inventory or see your health etc.
I'll see if I can add that in (setup of the interface). Been an eternity since I touched the editor (though I still remember half the console commands oddly).
[edit]
Fixed. Had to go read some super old tutorials I have on my computer, but I found the necessary info. Link in first post updated, so be sure to re-download it if you downloaded the earlier version. Tested on my PC and the user interface should now work.
Of note: If everything seems very well lit when you start the FM, crank down your gamma until things look much darker.
Note 2: Whilst my primary focus time wise these days is on full blown game development, every now and then I go and add little things to it so if I add anything to it in future I'll upload new versions etc and make a mention in this thread.