romlister can pull out that information for you, or most of it anyway.
http://www.waste.org/~winkles/ROMLister(sorry, every time I see the word "list" come up in the forum here, I am obligated to say the words romlister)

You could do a CVS output format against the entire list of games to get something like this:
name, romname, #buttons, controls
(Medal) Yumefuda [BET],yumefuda,6,
005,005,1 & 1,joy4way
1 on 1 Government (JAPAN),1on1gov,6,joy8way
1000 Miglia: Great 1000 Miles Rally (94/06/13),gtmra,1 & 2,joy8way & dial & paddle
1000 Miglia: Great 1000 Miles Rally (94/07/18),gtmr,1 & 2,joy8way & dial & paddle
10-Yard Fight (Japan),10yardj,2 & 2,joy8way
10-Yard Fight (World),10yard,2 & 2,joy8way
1941 - Counter Attack (Japan),1941j,2 & 2,joy8way
1941 - Counter Attack (World),1941,2 & 2,joy8way
1942 (First Version),1942b,2 & 2,joy8way
1942 (PlayChoice-10),pc_1942,2,joy8way
(the # of buttons has stuff like "2 & 2" because it's listed in both controls.dat and mame's xml data)
which you could then import into excel or something to examine the data you want.
The simul player data isn't an option in the cvs output screen though. that could be changed, or you could do separate lists with just that info.
I'd be happy to work with you offline about anything you need.
BTW: I love retrogui! that's what I'm using on my cocktail machine, although I had to create a custom cocktail machine for the graphic.