To Kill, or Not to Kill; This is a Question?

As a middle-grade writer, I'm constantly wrestling with the issue of whether or not to kill someone. In my story, I mean. Particularly at the beginning of a story. I think the reason parents are either rotten or absent in middle-grade novels is because it's a fast and easy way to engage reader sympathy. Somehow, I have to make a reader care about my protagonist within the first 10-20 pages. I can do this by:
Creating a burning, unanswered question. 
Pitting the world against them. 
Making them orphans.
Harry Potter does all three of these things within the first 20 pages. Percy Jackson hits the first two and compounds the sympathy by adding Smelly Gabe in place of a father.

In Return to Exile (only two more weeks to release!), I gave Sky, my protagonist, great parents and turned their very goodness into a roadblock. But this took time. To get immediate reader interest, I relied on burning questions and a cruel world.

It's hard to work strong adult allies into a middle-grade novel, and keep them there, because the reader will always be asking "why in the world is that kid in charge?" And most the time, the answer to that question feels very contrived.

If anyone knows of other things that work well in engaging immediate reader interest, other than the three things I've listed, I'd love to hear about it!