There's too much in here to catch up on, and I'm sorry if someone has already said this, but:
to all who insist that the Imperial system is more practical etc., 12 being more easily divisible than 10 and so on:
Then please stop using the decimal system for everything else. Following that train of thought, people living in countries using these units should mean decimal one hundred and fourty-fours when talking about hundreds, and dozens when they talk about tens.

Otherwise I think that everyone should use whichever one system they're used to, and be able to convert to Metric units when necessary, and vice versa. The only reasons why Metric units are more practical are that people around the world generally use a decimal system for numbers and scalability, which I think someone mentioned already. You can, of course, use megafeet and kilopounds, but it sounds and feels weird. Now that I think of it, that's pretty much the same argument as the first one. Perhaps someone should think of special Imperial prefixes that fit better, i.e. are based on 12? But what should they use? Latin and Greek are already occupied by the Metric units, and to avoid confusion they should choose other sources, or simply make the words up. Does anyone know if there perhaps already is such a thing?

Fuzz"hundredweight!=100 weight units, or am I wrong?"pilz