That is about the dumbest thing I've ever read. Will a .223 kill all the game you listed sure, it will kill bear and elephant as well if you hit them in the right place. That fact is it doesn't make the .223 Rem the best tool for the job. To ingnore any reports of wounded game is stupid, don't ignore them find out if it was bullet construction or poor shot placement. Learn from others mistakes as well.
You don't have time to learn to handle recoil! You don't have time to shoot then either. There are plenty of rifles out there better than the .223 Rem for elk and moose that will not kill your shoulder. 6.5X55, .260 Rem, 7mm-08 Rem, .30-30 Win, and .35 Rem come to mind. Besides if you ever stood next to a dead elk on the ground you would want a bigger cartridge if you have any common sense.
Refusing to listen about bones and construction just shows ingnorance as well. Premium bullet construction is what makes your .223 a better game killer than it should be. Varmint bullets have no place in a rifle you are hunting deer with. Proper bullets and proper bullet placement are key in hunting for securing your game.
Since I know you were probably just stirring the pot, I thought I would help out a little more. I have no problems with the .223 being used to hunt with as long as it is legal where you are hunting. I would use it at least once for pronghorn and possibly mule deer if it were legal here with a Nosler Partition or Barnes TSX bullet.