How would a dragon dive bomb?

[Timely Drought]

Hover doesn't seem to have been mentioned. You said you had a set spell list, are feats also set?

Hover is a great ability dragons can have. Spellcasters will not be able to target their spells if the dragons remain far enough. Ranged attackers will get hideous miss chances. The dragons can then blast away with breath weapons from above at a leisurely pace, and drop rocks and spells while recharging. If one of the PCs tries to get out of the floating debry area to get a good view, and leaves the rest of the party behind, one of the dragons can maintain the hover while his two buddies fall on the lone PC and tear him to pieces.

While they're hovering, they can form a triangle around the group. Though they need to be at 20 feet high to maintain the hover, and the total concealement is at 25 feet, they can use a diagonal distance to avoid being spotted. They just need to make sure they have no one directly beneath, and with three hovers around the group with each radius extending to 60 feet, that shouldn't be too hard. Once the perimeter is set up, they just need to check for lone PCs fleeing due to fear. If not, they can bombard weak-willed PCs with suggestions to flee the battle. When one of them goes, two dragons fall on him while the third keeps the rest of the group in the debry area. This keeps them from seeing where their companion went and that he is being beaten into a bloody pulp and desperately needs their help, though they might hear the blood curling screams.

Edit: Sorry, missed that dragons have blindsense, not blindsight. So suggestions wouldn't work unless a hovering dragon got close enough to see and be seen by the target.

HOVER [GENERAL]

Prerequisite: Fly speed.

Benefit: When flying, the creature can halt its forward motion and hover in place as a move action. It can then fly in any direction, including straight down or straight up, at half speed, regardless of its maneuverability.

If a creature begins its turn hovering, it can hover in place for the turn and take a full-round action. A hovering creature cannot make wing attacks, but it can attack with all other limbs and appendages it could use in a full attack. The creature can instead use a breath weapon or cast a spell instead of making physical attacks, if it could normally do so.

If a creature of Large size or larger hovers within 20 feet of the ground in an area with lots of loose debris, the draft from its wings creates a hemispherical cloud with a radius of 60 feet. The winds so generated can snuff torches, small campfires, exposed lanterns, and other small, open flames of non-magical origin. Clear vision within the cloud is limited to 10 feet. Creatures have concealment at 15 to 20 feet (20% miss chance). At 25 feet or more, creatures have total concealment (50% miss chance, and opponents cannot use sight to locate the creature).

Those caught in the cloud must succeed on a Concentration check (DC 10 + 1/2 creature’s HD) to cast a spell.

Normal: Without this feat, a creature must keep moving while flying unless it has perfect maneuverability.