1. briefly, what did cavour get from napoleon here at plombieres?

Count Cavour (10 August 1810 – 6 June 1861) was a chief minister of the Kingdom of Piedmont-Sardinia and an important figure in the process of Italian unification in the 19th century.

On 21 July 1858, he has entered into a secret agreement with, Napoleon III, the French Emperor. Though this agreement was only verbal and left no concrete evidence, it is sometimes referred to as the Treaty of Plombières.  

As a result of this agreement, France and Piedmont became allies in the confrontation with Austria. Cavour received support from France with the goal to free Italian peninsula from Austrian influence and thus move further to Italian unification.