macOS plist question

[larswik]

My friends are coming this weekend and we are doing a little role gaming. I want to polish off my Xp Calc program before they come. Everything works fine with it right now. But I am adding a 'Death Certificate' button. So when you get a kill you can press the button and a window pops up. I then enter the information, for Experience Points, any Treasure, notes and a time stamp which I save as an object in an NSMutableArray. They enter information in to a few 'Wrapping Text Fields'. At the bottom of this window I will have a left and right arrow to cycle through the saved past kills, by cycling through the index's of the array.

Question:
I am already using a plist with this code. I use this to add and subtract skills from a NSPopUpButton.

-(void)loadPrefsAtStart{
   prefs = [NSUserDefaults standardUserDefaults]; // *******************    Load Prefs at start
    filemgr = [NSFileManager defaultManager];
    fileSavePath = [@"~/Documents/XPCalc.plist" stringByExpandingTildeInPath]; // Sets up the default path to the file.

    if ([filemgr fileExistsAtPath: fileSavePath ] == YES){
        skills = [[NSMutableDictionary alloc] initWithContentsOfFile: fileSavePath]; // it reads the file into the Dictionary
        for (NSString *i in skills) {         //  for loop to loop through the keys if the Dictionary and add to popUpButton
            [popUpButtonDisplay addItemWithTitle: i];
        }
    }
    else {
        skills = [[NSMutableDictionary alloc] init];
        [skills writeToFile: fileSavePath atomically:YES]; // if it can't find it, it writes a blank file.

1. Can / should I have more then 1 plist? So 1 plist for skills and another for a Death Certificate?
2. If I use 1 plist must I save everything at the same time, both skills and Death Certificate. Or can I have 2 different save buttons on each NSWindow?

I am sure a plist can hold many items, but I am guessing you have to read everything and write everything at the same time.

I tried to find information on using many plists but the info was hard to find so I am asking here how to start this project tonight on the correct path.

Thanks