I only have the one HDD in the list, so is there anyway for it to just boot to OSX without Darwin having to ask me anything? As it is now, I have to press enter twice every boot.

replace the No by Yes (case sensitive) in your /Library/Preferences/SystemConfiguration/com.apple.Boot.plist and reboot to check
if needed remove timeout key + string


?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Kernel</key>
<string>mach_kernel</string>
<key>Kernel Flags</key>
<string>idlehalt=0</string>
<key>Boot Graphics</key>
<string>Yes</string>
<key>Graphics Mode</key>
<string>1280x1024x32</string>
<key>Quiet Boot</key>
<string>No</string>
<key>Timeout</key>
<string>8</string>
</dict>
</plist>