Besides spanish soldiers who were in place in spanish america to make sure rebellions were quelled and pirates didn't steal riches on their way to spain, what other powerful institution was in place to make sure all people practiced their faith in the only way deemed appropriate and acceptable by the catholic church?

Some ways the Catholic Church ensured all people practiced their faith was to establish missions and missionaries. The missions helpful set up local infrastructure like schools, farms, and hospitals. The evangelical campaigns waged by the Spanish paved the way for mendicant orders such as Franciscans, Augustinians, and Dominicans.

from the conditions of the working class in england by friedrich engels,the main idea is :

manchester's leaders hoped to oppress its working class to benefit factory owners.