WarFoundry searches a number of specified data folders for .system and .race files. Eventually they'll be in a preferences section so that people can specify their own, but currently it loads from a folder called "data" within the app directory. There's a couple of simple files in the "testdata" folder of the WarFoundry API tests that you can use for now. Once the app has loaded then you'll probably need to go "File > Change Game System" to pick the game system.
In terms of that weird window resizing, I've never had that occur before. Then again the first things I do with Windows are to get rid of the "Fisher Price blue" interface and reduce the size of the title bar. I'll have a look in a minute and see if I can find anything.
Maybe I still need more information in the Wiki on getting WarFoundry running with data
[edit] It looks like something moved your buttons. The form should be 320 by 170 with list being at 80 by 8 with size 216 by 95 and the buttons at 8 by 112 and 192 by 112 and sized 80 by 24 and 104 by 24 respectively. I don't know what would cause it to move things and edit the code, but I've just opened the dialog and read those files without it editing anything.