Green Slime, good point on the duration of Divine Shield. Your suggested feat/class progression looks good to me. Although Power Attack and Divine Might combo is still calling me
Kjenks, Combat Reflexes and Hold the Line is a nice combo and worth considering, but I'd be tempted to take Karmic Strike over Hold the Line.
Now, is there any merit in taking Mounted Combat when riding a dragon? Or is simply maxing out Ride skill sufficient?

Kjenks, Combat Reflexes and Hold the Line is a nice combo and worth considering, but I'd be tempted to take Karmic Strike over Hold the Line.
Now, is there any merit in taking Mounted Combat when riding a dragon? Or is simply maxing out Ride skill sufficient?