What is the weight limit on pergo flooring?
It can basically take any amount of weight.  Well I am sure there might be a theoretical limit but nothing you are going to possibly have will effect it.  The key is to allow for some minor expansion gaps on your out walls and to never nail/screw/whatever anything into the flooring.  

You have to make sure that no cabinets, shelves, or anything else that is anchored to the floor.  Other than that you are good to go in a mobile home.  The only issues I have seen with Pergo is when people screw down an island on top of it or very large rooms - 20 feet plus squared.