1) angiotensinogen levels are increased during pregnancy and estrogen containing oral contraceptives, which increases blood pressure and might lead to stroke.

2) because the blockade of ANG receptors doesn't interfere with the inhibition of bradykinin. Which causes dry cough, headaches etc. 

3) ace inhibitors block the conversion of ANG 1 and 2 and it also Inhibits the breakdown of bradykinin which decreases blood pressure. 

4) AT1 receptors, yes they do have a direct effect on ANG 2.

5) kinins cause vasodilation and arterious dilation, Decreasing peripheral resistance and blood pressure. Bradykinin camp, NO, IP3, prostaglandins etc. 

Natriuretic peptides also cause vasodilation and arterious dilation. 

6) B2 receptors. 

7) Natriuretic peptides are used in heart failure, because they limit sodium retention via increasing glomerula filtration and Decreasing the proximal tubular sodium reabsoption. 

8) neprilysin is the enzyme that breaks down Natriuretic, it's antagonist is sacubitril that increases the circulating levels of Natriuretic peptides, limiting sodium reabsoption in heart failure. 

9) vasodilators- PGI2 AND NO

Vasoconstrictor- endotheluns