Verified answer

1) The Spanish wanted to create a cash cow. The Spanish colonies were designed for immediate profit. They Spanish crown wanted gold, silver, jewels, pearls, and anything else that wasn't nailed down. This required a huge military presence to guard all that wealth and to control the workers to make sure they didn't steal. It also required a strict, central authority to make sure things were running well. It was like a business. The idea was to squeeze every last cent out of the colonies.

Contrast that with Britain took a different approach. It was one that was first proposed by Sir Walter Raleigh. The goal was a long term project to expand the boundaries of England by creating settlements in North America similar to what was at home. The idea was that long term this would provide England with a larger population base, agriculture base, and industry. While not as immediately satisfying as gold, it would increase England's raw industrial, military, and economic power in the face of its larger European neighbors.

Because of this, the English colonies needed very little military presence except for the Royal Navy to keep the sea lanes clear. The English colonies were predominantly farming communities which could manage themselves like villages back in England. Most troops were locally raised and served under a royal governor.

Because there wasn't the serious flow of money coming out, strict central authority was not needed. The colonies were allowed to develop their own legislatures and courts which they modeled on England. They built schools and universities. This policy was called intentional neglect by Prime Minister Thomas Walpole.

2) The Northwest Passage was the holy grail of exploration. Until the Suez Canal opened in the 1860's, the only strait sailing route to Asia was around the Southern tip of South America or Africa. Both these routes are so incredibly rough that a lot ships were lost back then. Even modern ships are careful in those areas.

Due to weather theories that may or may not be correct, a strait route across North America was thought to be a potentially more calm. Controlling such a route, would give a massive trade advantage to nation that had it. Their ships could go from Europe to Asia safely.

Of course, no such route existed. One sort of does now because the Polar ice caps are melting.

However, the search for this route obsessed and drove exploration of North America. Henry Hudson went up the Hudson river valley looking for it. Samuel Champlain went down the St. Lawrence River and into the Great Lakes looking for it. Spanish and French explorers went up the Mississippi looking for it. The pattern of exploration was dominated by the search.

Even Lewis and Clark, in 1805, planned their route of exploration around the possibility that the Missouri river would turn out to be it. It was also the last major expedition to look for it. By then, enough mapping had been done to know it was essentially hopeless.