The goals of pre marital counseling are to help couples identify their commonalities and differences, and to negotiate some terms prior to getting married, living together or raising a family. New couples are generally much more adaptable, and willing to put the work in than older couples, who are more set in their ways and harbor resentment. Setting things up for success in the beginning is a far more effective solution, for when conflicts arise down the road, the couple may already have an agreement worked out, or, they have the tools to make a compromise or negotiate an agreement. Couples can refer back to their pre marriage counseling as needed. This may re strengthen their bond and bring back feelings loving feelings. Also, since this couple has already been through counseling together, they are much more likely to return to counseling should they need it.
Yes - it helps couples unearth past issues and family dynamics that may affect their relationship in the future. Many people do not realize the family habits that are engrained in them until they live with another person with such intimacy. These differences can be subtle or large, but they are always there! Counseling is a great way to address these things!
I think any kind of therapy that makes you understand yourself and your partner a little better is useful and v¡necessary. I regret that schools teach us little about emotions and communication. Therefore we have to learn it as adults if we didn´t have good examples that showed us how to deal with your partner in a nice way.