Would this be safe with reptile pets in the house?
Yes the product does not affect reptiles.
how many do you need for a 5 room ranch?
It all depends on the square footage of your area. We recommend you use one in each room.
is the unit water proof, out door use, 60ft x 25ft how much are will it cover
This is not a waterproof product. Coverage will vary depending on the material and thickness of your walls.