Since we speak at least one common language, perhaps this illustration will shed some light on what Catholics gain by Marian consecration.

<h3>Encapsulation</h3>
 Mary is not the head of the Catholic Church, she is however, the superclass from which all Christians descend.  In my Marian consecration, each day I promise to devote all my prayers, actions and sacrifices to her to further the work of her Divine Son. My public methods, my private methods and my protected methods all should point to Christ.  I do all these things poorly, in imitation of she who did these things well and was blessed by God for her faith and purity of heart. 
<h3>Polymorphism</h3>
 Marian consecration takes on many, many forms.  The form you mentioned, the form I did 9 years ago at one of the lowest spiritual points in my personal life, is the consecration of St. Maximilian Kolbe who spread devotion to the Miraculous Medal given to St. Catherine Laborre at Rue De Bac (in the middle of Paris).  He took the message from Poland to Nagasaki and finally died in a concentration camp in Auschwitz, but his particular devotion of starting "Marytowns" spread all the way to Libertyville, Illinois.  [Marian consecration](http://www.fisheaters.com/totalconsecrationmontfort.html) really goes back to St. Louis De Montfort in the 18th century.  Devotion to the Heart of Mary comes straight out of the Bible, who Simeon foretold a sword would pierce.  Is the Heart of Mary, Jesus is that passage even referring to Mary?  Who can know such things.  Fortunately, through the grace of polymorphism, we can overload the devotion with as much as we want and never find it failing to point to Christ. 
<h3>Inheritance</h3>
 Mary's ancestors, as well as Josephs were through the Davidic line. If we [take her into our home](http://bible.cc/john/19-27.htm), if we esteem her like Solomon [esteemed his mother](http://bible.cc/1_kings/2-19.htm) then we do what we can to help our cause to become coheirs to the kingdom.  However, the abstraction fails, we're not gnostics, we don't gain access to Christ's protected methods (those hidden outside of revelation).  But we can meditate on them.
<h3>Abstraction</h3>
 I think this hits your observation about indirection.  When we conform ourselves to Christ,  we want to take on His attributes.  You want to be in Him?  You want Him to be in you?  Learn from the one who took Him not only into her home, but in to her body.  Mary is the Church, the Church is the bride of Christ, the Church is the Body of Christ.  There's no way to understand these mysteries, except through a mirror abstractly. 

I hope that helps, it was fun to write but probably exceptionally useless in the long run.