I stopped using windows some time ago as developement is so much faster on both Linux and OS X so it has been a long time since I have looked at keepResident. An alternative is to the use "sun.awt.keepWorkingSetOnMinimize" system property and set it to true. If you are starting JDeveloper this will look like:
This will prevent JDeveloper from being swapped out when minimized; but it wont help with the other memeory issues. For that you need anything else bug Windows as you developer platform.