The file in those folders are just what it says : Support files for each application. If you use the app, you should leave the folders alone. Deleting them may cause the app to stop working, if necessary files are no longer found.
System files and applications take up very little space, and you will not save much space by trying to find stuff to trim there. Generally, the biggest pile of stuff on your storage is ... your stuff.
If you've got a Unibody MBP, then it's very easy to replace the hard drive with a larger drive (preferably an SSD, which will give your Mac a speed boost and new lease of life). You might also want to think about buying Snow Leopard from Apple and then updating free to Yosemite. More RAM would be helpful - again that's quite easy to do. This would give your Mac a whole new lease of life, and give you access to the latest features like iCloud.
At the very least, there are some very cheap low-profile USB flash drives, or if your Mac has an SD card reader, you can get drives for that slot.
It's better to make your storage fit your data rather than trim your data to fit your storage.