If you have problem with older games, try to install them using the WHDLoad installers found on www.whdload.de
Direct link to Battle Chess installer is here
You can add whatever directory to AmiKit. AmiKit is configured to add PC drives at startup by default which means your "C:", "D:" etc. partitions should be visible and accessible within AmiKit desktop. The PC partitions in AmiKit are displayed as "WinDH_C:", "WinDH_D:", etc. OR - if the partitions have additional names - the names are used instead (like WinXP: or whatever). Even if you plugg an USB flashdisk into your PC before you start the emulation, you should be able to read/write this flashdisk using AmiKit.
If your programs are stored in virtual harddisk (a hardfile with .hdf suffix), then simply add this hardfile to AmiKit. Run the AmiKit launcher and press "Configure WinUAE" button. Go to "Hard drives" settings, select "Add hardfile" and enter the path to your hardfile you want to add. You might want to save your new settings - go to "Configurations" settings where you will see AmigaForever configurations entries only though. You have to press "Save As..." button and save your new AmiKit settings to your AmiKit directory, eg. "C:\Program Files\AmiKit\WinUAE\Configurations\AmiKit_v1.uae". Then everytime you hit the "Run AmiKit" button, your new settings will be used automatically.