if you have a few bags you could line them up from left to right about 3-4 feet apart. then assign a different techinque per bag, start on the opposite side of the room then shuffle uo to the first bag, strike it then shuffle back to the wall and repeat a few times.
why dont you start correcting yourself first. it may sound weird but if you do a kata step by step and find out what you need to correct on your self, it will give you a better idea on how to correct them
lets see... about 13 of those are on my list.. i think i could add about 3... you wear your karate uniform half the places you go. you have a punching bag in your office. and you cant resist kicking the manikins at a store.
like about three years ago back when i was 5'1 i had to spar this person who was 6'2 and like 100lbs heavier than me (it was more of a wrestling match). so he charges i dodge it then try a hip throw (good technique for people the same wieght.) he trips me. so i just go and like charge his stumach. he keeps trying to throw me down by by like throwing me two feet back but i keep landing it untill he throws me behind him and hit the wall . anyways enjoy my suffering
in our dojo we have this game thats almost the same as yours but we play it with two throwers, one person by the wall, and the rest ball shaggers. we use fifteen tennis balls which makes it challenging and fun.
my instructor had this whole program where you pick the kids up from the schools and they stayed at the dojo until 6:00 there was a finishing homework part and 2 hours of class differently depending on the day.
how about putting up a sign on a resturaunt that says: the best thing you can give your child...confidence if its an adult youth school. it worked for our school.