I have shot matches somewhat like you describe. I went to an IDPA match where they announced, we are going to conduct two matches at once. If you want to follow IDPA rules sign this list, if you want to participate in the "tactical match" sign this list. Their gripe was the same as you, there were guys that were not allowed to use their actual carry gun because of IDPA rules. Since I thought I was going to an IDPA match, I chose that route. However when the results were posted, all shooters were lumped together meaning I was shooting against guys using compmensated guns, no concealment of their holster, etc.
To answer a couple of your questions;
"if your mag has the capacity to run through a stage with no reloads, why reload? "
Simply to practice reloading. Some of the stuff in these matches might not make sense on the surface but the idea is just to practice basic skills and encorporate those into the match.
The reason all these "games" have so many rules is because no matter how much the designers want to make the "games" practical, there will be gamers. They will take every rule to the limit and turn it into an equipment race. Even your idea has rules and I am sure if you actually try this you will end up with a lot of rules.
I think if you try this, you will have a lot of fun and if everyone participates in the spirt intended, it might be a valuable training tool.
You know the rest. In the books you have read
How the British Regulars fired and fled,
How the farmers gave them ball for ball,
From behind each fence and farmyard wall,
Chasing the redcoats down the lane,
Then crossing the fields to emerge again
Under the trees at the turn of the road,
And only pausing to fire and load.