DFC
Cutthroat Truther
2F4 being an overhead is my "If you must" option, for an overhead. It doesn't really change much in the grand scheme, but it'd shut up some of the people who think he absolutely needs it. Truth be told, they need to fix the 2, more than the F4. 2 whiffs a lot. I was shocked when it was going over TREMOR in my sets with a friend.What do you all think of 2F4 being an HDK overhead? Imo the last hit looks like a legit overhead. It almost makes as much sense being a mid as Shinnok's S3 being mid (srsly lol). Commando Kano is also missing a B2 and F2, maybe one of those could be an overhead? It doesn't have to be a starter - I really don't want Kano being another stupid coin flip character.
As for your other point, I think the way variations work(at least it looks this way by looking at Kano), is that you can't attach more than two attacks to a single input. You have standard B1, and Cutthroat B1 for example. As it stands, the only starters that don't have variation specials are 1, F1, 2, 3, F3, B3, 4, and F4. so if you were to give Commando a unique string, it'd probably replace F1