I have the same problem with my kicks, my cousin suggest a strech to help with that. You have to go as low as you can in a F/B splits and bend your front leg, which will let you go down further.
In my studies it started in the Tang' dynesty of China. TSD and TKD both started at this time the only difference is TKD started as a sport and TSD started as the MA behide that sport.
It depends on the people sparring, usually I hit like I was in a real fight, unless I sparring someone of an inopropreat age. Also you can use grappling if your good enough, I wouldn't recommend it.