So recently I've decided I want to do some Seminars and training with my AR15 but I was wondering if the things I have done to my AR15 are okay mods and won't cause me problems during training/practicing. Here's what I have. Bushmaster XM15-E2S Carbine Length 16", Daniel Defense EZ Car 7.0 drop in rail. (non free floating). Magpul Rail covers. Magpul RVG. GGG Rear Back up Iron Sight. Magpul CTR Stock. And the interals are stock that came with the gun. My few concerns are the free floating rail system and the Carbine Length. I notice a lot of people use a MID length and I wasn't sure if many people take a carbine length to classes. The next few items I plan to get is a sling and some kind of Sling adapter for a single point. Any suggestions? I wanted to make sure I'm going in the right direction with my weapon system.