You would actually only need to put the buttons in for player 1 and 2 and not need any other info in the sf.ini. I'm not sure if you need to make a copy of this file and call it sf2.ini etc for each of those games. Hopefully someone will be able to help on that.
neogeo.ini
neogeo.ini fixes all the neo-geo games. Otherwise, parent-clone works, so SF.ini fixes SF and all the clones of SF, but if SF2 is another parent, you need to copy and rename the file (but you don't have to re-type everything).
Also, in your mame.ini file (Run mame with the -cc option if you don't have one - you need to change the following two lines -
### Windows path and directory options ###
ctrlr_directory ctrlr
### Input device options ###
ctrlr Mine
(or whatever you named the ctrlr\xxx folder)
Also, the tab set values override the ctrlr.ini files so for any game that you set inputs using the TAB menu, you need to delete the gamename.cfg files before MAME will use the new assignments. This will also delete any dipswithch changes you have made, so you will have to reset those.