As to the question of leaking around the pop-up
The original system in my estimation is ideal for the prevention of leaks
. Key to that are two factors
a) Make sure the pop up is fully extended and therefore forming a taut (tight) fabric surface
b) Maintain the velcro closures and vinyl 'windows' so no cracking can occur and therefore allow penetration of rain.
Isn't it a lovely feeling to have all those 'ducks in a row' before the rain starts, and then enjoy the fun and fury of a rainstorm on your camper roof??????