I think firearms are a lot like cars. When you first start modifying, you install a bunch of parts "just because." Few--if any--of them are functional or really do much to make the car actually look/perform better.
Since it's your first firearm, you'll learn as you go. I've taken all those types of accessories off my black rifles. No more vertical grips, flashlights, etc anymore. All I did with my GSG-5 was modify a Knights Armament handguard to fit. The vertical grip and flashlight are now collecting dust on a shelf.