For max. Speed, should my boat be propped to reach max. RPM right where the engine produces its max.HP?

For all about best use, yes. Boat's can't shift (nor would it add top speed), so generally speaking, you prop as big as let's you reach max RPM for the engine.

If you propped lower, you'd be leaving speed on the table (but gain acceleration), and higher, you'd actually be going slower as the engine wouldn't have the power to spin it up, and you'd again be leaving speed on the table.

Thanks for the reply SaberTooth. So in theory, if my top rpm exceeded the dyno rated rpm for peak HP by more than a couple hundred rpm, I should pitch up the prop?

Yes.

To clarify what SB stated....yes....

My personal preference is to error on the slightly underpropped side of things in the most optimal weather / load conditions. Then as loads (passengers/gear) increase or summer heat rolls in performance should still be near peak HP for given atmoshperics.

Yup

Since you have dyno sheets, it will also depend on where and how fast torque is falling off.
Post a pic of the dyno sheet

You'll want to do testing with 'real world' scenarios as well. 3/4 tank of fuel, passengers, cargo, etc.

^This

Here's the dyno info