1st Question:
The Framers wanted a division among the branches of government, in which some power was given to the judicial branch, some to the legislative branch, and some to the courts. Compared to a presidential system, the legislative branch in a parliamentary system has much more power.
2nd Question
The framers needed to find a way for representatives to fairly represent both population and states, meaning that although state population affected representation, it wouldn't be so much so that small states like Rhode Island had almost no voice. To do this, the created a bicameral legislature, with each state having equal representation in the Senate and the House having numbers of reps based on population. <span />
The most common source for this would be the Second Treatise on Government by John Locke, the philosopher who inspired things like the French Revolution and the American Declaration of independence, precisely because of those ideas that you mentioned.
<span>a group of words established by usage as having a meaning not deducible from those of the individual words</span>
24th amendment "The right of citizens of the United States to vote in any primary or other election for President or Vice President for electors for President or Vice President, or for Senator or Representative in Congress, shall not be denied or abridged by the United States or any State by reason of failure to pay any poll tax or other tax.The Congress shall have power to enforce this article by appropriate legislation."
look at the bold
In 1772, groups of the colonists began to create Committees of Correspondence which would lead to their own Provincial Congresses in almost all the colonies I think
