Do you know what it weighs (ready to fly) compared to the 5.3 - 5.7 pound [2400 - 2600g] estimate in the manual?
If it is heavy, are there any areas where you can remove wood or drill holes to make it lighter?
Since you will hand launch, ground clearance is not a problem. Maybe a 13x6 prop would help limit the speed and give some braking effect when landing.