Hemp is the world's strongest natural fiber. It has been used to make cloth and rope for over 10,000 years. Hemp was the first crop ever cultivated for textile production. Hemp cloth is stronger, longer lasting, more resistant to mildew, and cheaper to produce than cloth made of cotton. Hemp ropes are known for their strength and durability. The original Levi Strauss jeans were made from a hempen canvas. Even Old Glory was made from hemp fiber. A 44 gun frigate like “Old Ironsides” took over 60 tons of hemp for rigging, including an anchor cable 25 inches in circumference. Hemp can be used to make virtually anything that is currently made of cotton, timber, or petroleum. George Washington and Thomas Jefferson both grew hemp. Ben Franklin owned a mill that made hemp paper. Thomas Jefferson drafted the Declaration of Independence on hemp paper. Until 1883, more than 75% of the world's paper was made with hemp fiber. In 1937 Popular Science magazine called hemp "The New Billion Dollar Crop." Then the big money people struck out to protect their interests. Newspaper publisher William Randolph Hearst led the crusade to ban hemp. Hearst owned millions of acres of prime timber land and a machine that simplified the process of making paper from hemp had just been invented. Hearst used his power as a publisher to create public panic about the evils of hemp and marijuana.
I'm pro-legalization, but you need a reality check.
First, while hemp is a good natural fiber, synthetic and natural/synthetic composites are much stronger, and in all likelihood cheaper as well. Hemp rope may have some use, but you are basically telling us how the horse transportation rules in the age of modern automobiles. Unless you tightly constrain and qualify that, it is essentially nonsense in the general case.
Second, hemp is an INFERIOR fiber for a great many things you list, such as paper. Any paper engineer can tell you that the best general purpose paper base is soft fir pulp. You can make paper with lots of things, but in the real world soft fir pulp is a superior solution as a matter of science and engineering. Why the hell would anyone want to use hemp for paper today?
Lastly, you are essentially setting up your own little strawman to support the legalization of marijuana. Nothing you've written actually qualifies hemp as useful. If you wanted to make that argument, you'd lose by and large. The reason for legalizing marijuana has nothing to do with who grew it and what it was used for a couple centuries ago.