Right, delete everything in the folder and the subfolder, not the folder or subfolder itself.
It is supposed to give you a performance increase by doing this little clean up, however when you first fly a mission due to the game rebuilding the folders you may notice slight stutters, the increase will come, according to forum posts, when you fly for a second time.
I did it, but I think its more of a valid thing after for example a patch (clean out the old stuff and rebuild with the newest), since I bought the game with the last patch already on it it didn't really make much of a difference for me.
If I may ask, and yes it's of topic, how do you like that water cooler, doc?
I know you must like it otherwise you wouldn't have it

, just asking, a bit torn right now between buying a Noctua NH D14 or a little watercooler like you have.
And I have to agree, don't worry about cluttering the forum. You have a question, so ask, maybe others have the same question as well and instead of digging around there are actually people here who are willing to answer to their best knowledge, even if it has been asked before and not sit on a high horse and tell people to go shooo, you are not worthy.
Remember, the higher the horse the harder the fall.