I'm creating and adjusting some layouts atm and am really happy to see the ability to use GIF's, but is there a way to make them transparent (for flashing arrows or a moving joystick) or would it be possible to implement it if not 
I had a look at the wrapper and it does not appear to be an option  
 Others...
Others... Thanks for the info. I am working on the reported issues  

I done it.
But I don't know how. 
I added some Additional and newer Catver.ini, Controls.ini, Nplayers.ini and it works
Keep in mind you need to do a 'Refresh Main Game list' to apply the extra data from controls.ini and nplayers.ini.
This will update the main (all games) list. If you want to pass this update onto you custom list then on the game lists tab choose the lists then click the 'Update all lists' buttonHere is the code logic when you do this:
If nplayers.ini (if present) then  it uses that to number of players /alternating etc
otherwise it will use controls.ini (if present) to set number of players /alternating etc
 TheGame.FInputPlayers
.....Then the following is set from the mame.xml:
    FName:                 string;       // rom name
    FRomOf:                string;       // master oder bios name
    FCloneOf:              string;       // master rom name
    FSourcefile:           string;       // driver name
    FDescription:          string;       // game title
    FYear:                 Integer;      // year
    FManufacturer:         string;       // manufacturer
    FGenre:                string;       // game genre
    FInputButtons:         Integer;      // control panel button count
    FInputCoins:           Integer;      // control panel coin count
    FInputPlayers:         string;       // player count, nplayers information
    FInputControl:         string;       // kind of game control
    FVideoScreen:          string;       // kind of video screen
    FVideoOrientation:     string;       // vertical or horizontal
    FVideoWidth:           Integer;      // width of the screen
    FVideoHeight:          Integer;      // height of the screen
    FDriverStatus:         string;
    FDriverColor:          string;
    FDriverSound:          string;
    FDriverEmulation:      string;
    FDriverGraphic:        string;
the rest is set from controls.ini (if present):           
    FControls:             string;       // game controls from controls.ini
    FJoyUp:                string;
    FJoyDown:              string;
    FJoyLeft:              string;
    FJoyRight:             string;
    FButton1:              string;
    FButton2:              string;
    FButton3:              string;
    FButton4:              string;
    FButton5:              string;
    FButton6:              string;
    FButton7:              string;
    FButton8:              string;
    FDetails:              string;
ACTION:
I will make a note on the config screen so this is more apparent.
I will add an option to right click to see all metadata on selected game so you can see current state.
I think that will help