3sweeties did an awesome job of answering your questions already, so I'll just pop in to say that DITHOR is your reading instruction for your dc once they are reading well.

Storytime will give an exposure to genres and to story elements in some of the guides, as well as teach CM LA skills, but it doesn't replace needed reading instruction for dc. DITHOR works on teaching specific needed reading skills - i.e. doing pre-reading activities to create a purpose for reading the text, giving guided literature discussions to help students gain a deeper appreciation and understanding of the text, giving vocabulary activities that teach different strategies to help discover the meanings of unfamiliar words in the text, teaching the story elements, teaching Godly character traits and how to analyze books with those in mind, doing creative projects to show what has been learned - anyway, you get the picture.
When I first began homeschooling, I was appalled to see how many homeschooling curriculums skip reading instruction once dc are reading well. It's almost as if they think once a child is reading well, there's nothing more to be learned!

Believe me, reading is more than just sounding good when you read aloud, and it's more than just blowing through a pile of books for free reading time on your own. I've been looking ahead at high school lit and comp lately - I can see why DITHOR won the award of being in Cathy Duffy's Top 100 Picks - it does an awesome job of teaching reading instruction and preparing our dc for all that is ahead of them.

I'm so glad we're not going to be in for a shock when our dc get older - DITHOR will totally have prepared them for it, which means I'll be able to keep homeschooling happily - gotta love that.
In Christ,
Julie