Pondering tantrums and poop

I've been reading some parenting books over the past several months.  As I try to point out to my husband, it's not that I'm looking for an instruction book or a recipe book for child-rearing, I'm just trying to get some fresh ideas and new perspectives.  When the boy throws tantrums, resists going to Sunday School, and becomes fascinated with the word "poopy", I need a little professional know-how.  When the girl throws tantrums, climbs everything but the walls, and repeatedly puts her hands into her poopy diapers, I need some other experiences to draw from.  Ah, tantrums and poop.  The stuff of mothering young children.  

Most recently I've read:
Parenting with Love and Logic - a great book based on the theory of raising your children to be independent and thoughtful from the get-go.  I think I need to buy this one and re-read it.
Loving the Little Years - a "you-can-make-it-through-the-tantrums-and-poop-years" pep talk with good insight.
Raising Cain - a fabulous book about raising boys that I've read every year since I started raising a boy.

Here are a couple of the most salient points that I'm currently pondering:
Throughout the young years, parents need to maintain a relationship of authority with their children (not power; authority).  It's how we teach and guide them.  But in the span of a long life, the years of parental authority (say, eighteen years) are much shorter than the years of parental friendship (the rest of our children's lives).  During those young years, it's important to remember that we will have a relationship that leans more toward friendship much longer than our relationship is one of authority.  What exactly does this mean as far as parenting little ones and maintaining authority with the promise of a life-long friendship?  I'm still trying to figure the details of that one out.  

Boys need their moms.  But I've never been a boy so I don't understand all the specific needs of a boy.  In what ways will he need me when he's a pre teen?  A teenager?  I need to re-read that book again....

If we teach our children to make independent, thoughtful, responsible decisions when they are little, we are providing them a solid foundation for making good decisions as teens and adults.  For example, if I teach my preschooler to be responsible about picking up toys, he should (in theory) have the intrinsic motivation as a teenager to take care of his homework using that intrinsic motivation.  I love the idea of building these "habits" of good character but at some moments I feel like it's a tall order.  It's easier right now for me to tell the children what to do and what is right than let them experience the discovery of learning on their own.

And a gem from a sermon at our church last fall that I just can't stop thinking about:
When I became a parent, my children took over every nook and cranny of my world and in return, my husband and I occupy every nook and cranny of their world.  Especially in these little years, we are their safety, their love, their familiar, their everything.
Someday they will grow up and we will occupy respectively fewer nooks and crannies of each other's worlds.  
Someday we will start dying and will not share the Earth together. 
But...
God is the one constant in our lives.  God is the one with us from womb to tomb.  Mothers, fathers, sisters, brothers, husbands, wives... we don't all die at the same time.  The one thing with us for literally every second of our lives on Earth is God. 
And why would I not want my babies to start building a relationship with Him now?   They will be in His care much longer than they will be in mine.