All these sound like great proposals. Perhaps we could also replace the goal posts with a small circular metal hoop, and then maybe the players should be able to use their hands to throw and bounce the ball. Then we should replace the grass, maybe with some wooden gymnasium flooring.
Sorry, but I don't think your ideas will fix the mathematical problem caused by lack of scoring opportunities in football (:
Sarcasm aside, you're clearly stating that if my rules were to be used it would be a completely different sport. But no, compared to the current game of football it would be considered a different variation at most. Often when things start out they gradually change over time, usually for the sake of improvement. Some things move very slowly, some things a bit faster. Unfortunately, football and many other sports evolve very slowly... not because they are perfect as is, just because people don't like change. Since football is pretty much the oldest sport largely played it has many primitive features that have not been fixed yet, though it should be said that most sports (and games in general) suffer from some type of lack of foresight. One of the main reasons for such retardation in the world of gaming and sports is the lack of need for improvement, therefore such progressive thinkers that could influence such traits usually do not take part in the realm of games and sports. In the world of science and technology improvement is extremely important, so things tend to change fast there relatively quickly, even in the face of religious fundamentalism.
Honestly though, the changes i suggest are not even that extreme with the exception of 1 or 2 things. Mostly it is common sense fixes, but if you're so accustomed to something that seemingly works for you it is natural human behavior not to want change, and even bitterly fight against improvement.