You ask several questions here. I will briefly address each one. For more in-depth answers, I suggest that you submit them as separate questions.
Many English colonists in North America felt that the Stamp Act of 1765 was a violation of their liberties. First of all, this tax was passed by the British Parliament, a governing body in which the colonists had no representation. They felt that taxation was being foisted on them without any input by the ones who were responsible for the burden of this tax. Many colonists angrily responded with the argument that only their own representative bodies had the authority to levy taxes on them. Furthermore, as a tax on any official paper documents, many felt that this tax inhibited their ability to conduct business or engage in free speech. To add insult to injury, the Stamp Act said that violators would be tried by the Admiralty, rather than in front of a jury in a civil court.
By the 1760s, most British authorities felt that it was high time that the colonists paid their fair share in taxes. The recent war with the French was largely fought for the protection of the colonists. It was an expensive war that left England with many debts. Policymakers in London felt it only right that the colonists help pay for this. Furthermore, colonists generally paid much less in taxes than people in England did. Many colonial leaders disagreed with this. As stated above, they felt that it was a violation of their rights to have taxes levied upon them by a government in which they had no representation. For generations, the colonies would grant Parliament permission to collect taxes. The Stamp Act and other taxes of this period went against that policy. Many colonists feared that taxation without representation was an infringement of their basic rights as a free people.
Before the outbreak of the American Revolution, most colonists never conceived of breaking away from England. They considered themselves loyal English subjects who enjoyed the benefits of that status. However, these new taxes, along with the oppressive methods used to enforce them and punish violators, united many colonists against the crown. They felt that their long-held rights and liberties were under threat. This helped create a large movement that would eventually challenge English control over the colonies.
Lastly, Jefferson's statement in the Declaration of Independence that "all men are created equal" is a curious one for a slave owner to make. It was based on the Enlightenment notions of philosophers like John Locke and Voltaire. They claimed that all people are imbued with the same basic rights by God. In fact, the original draft of the Declaration had a section criticizing slavery. Jefferson believed that slavery would eventually be abolished. However, the need to unite the colonies, which included many pro-slavery and anti-Native American factions, trumped the larger philosophical premise of this phrase.