yahoo is most likely some temporary files.
com.facebook.orca is facebook messenger. i believe deleting this filepath would result in losing facebook messages.
try uninstalling applications you dont use so much.
miscellanous filepath usually contains "cached" informations from apps, such as pictures to help load graphics faster.
unfortunately at the moment we dont have a proper way to help reduce space taken up on the internal sd card, what you can try doing is "moving" apps to the external sd card to help free up space.
some apps do not like being moved to the sdcard, so if you receive any messages about apps not responding or closing repeatedly, try moving it back to the phone.