Its unlikely the fan will be sucked into the radiator but more likely the radiator will move towards the fan if not anchored down firmly enough.
No worries on the 2.8 fan breaking as there are actually about 7 blades and they are flexible to a greater extent and seem to be more moulded to the circular hub than the 2.5 which are also quite brittle.
My main reason for wanting electric is the mess the mud and water makes in the engine bay because of the fan
