Schools of Jurisprudence

Dear scholars, As-Salamu `alaykum! Despite the unanimity that characterizes the views of the four Muslim jurists (Imam Abu Hanifah, Imam Shafi`e, Imam Malik and Imam Ahmad Ibn Hanbal), they also had their different points of view. My question is: Does a contemporary Muslim have to abide only by the opinions of a certain Juristic Imam or can he/she follow the views of more than one Imam on different cases? Secondly, what are the method applied by each juristic Imam in reaching his opinion? Jazakum Allah khayran.

Dear scholars, As-Salamu `alaykum. Is it permissible to follow the ijtihad (personal reasoning) of one scholar on a particular issue and that of a different scholar on another issue when you know that the second scholar favors facilitation? Jazakum Allah khayran.

Respected scholars, as-salamu `alaykum.I am an imam in the US, and I am facing problems with the Muslim community here because when I do something, some seem to like it and others seem to dislike it. The community here follows different madhhabs [schools of thought] and sects, and some people are very critical to everything that is different from the madhhab they follow. Please advise me as to what can be done in this problematic situation.Jazakum Allahu Khayran.