In the books, Sam's loyalty to Frodo begins as that of a servant to a master. Not servile, but proud to be of service. It also develops into friendship and love, in the Aristotelian or Ciceronian sense--the love of one virtuous person for another, out of admiration for their virtue. In the end, Sam ceases to be a servant, marries Rose, and sets up his own family, becoming mayor and rising above his "servant" status.
The movie is not, in my opinion, slanted toward homosexuality. But the great failure of the entire sequence of movies is to understand what it means to be a servant, a master, or a king. There is nothing demeaning about such "service." Christians serve God. Warriors serve their king.
Aragorn is a great king in disguise, but he never fully emerges in that role in the movie. Faramir is a true knightly leader, but in the movie he is virtually indistinguishable from his brother, Boromir.
In the book, Theoden has been persuaded by Grima Wormtongue that he is no longer up to the job of being a king. When Gandalf speaks to him, he reminds him of his duty, and Theoden rises out of his moral sleep into greatness again. Once more, the movie hardly understand this.
The great deficit is that the makers of the movie have some understanding of concepts like love and duty, but they can't put them in the proper aristocratic terms. Aristocracy can be snobbish and effete, but it can also be great and noble. Tolkien had a tremendous admiration for true aristocracy: kings, knights, great ladies. There is no way to translate that into modernist terms. If you can't understand that loyal service to a great leader is noble and good, then you can't understand the basics on which Tolkien builds his tales.
Tolkien was a medievalist. Much of this can be found in the idea of the medieval war band or comitatus. Understanding the nature of the comitatus, as reflected in Anglo Saxon poetry, is a good place to start.
Now, I have to contest this. The movie Theoden was the most perfectly realized Tolkien character from the book, except perhaps for Galadriel and Gandalf. "We will not defeat them...but we will meet them in battle nonetheless." The Maybe you'd see this more in the extended versions. Theoden always overcomes his angst, and I thought PJ's Angst-ridden Aragorn was a little much. The book Ranger had no insecurities, just burdens and problems.