1. My rv pad is 2" off level when I started my auto level. I did end up with one tire off the ground slightly because dip in my pad, but the trailer leveled perfectly. Ultimately, you want to get all ,tires on the gound if possible. Each jack is heavy duty and can lift 5,000 pounds. I can tell you 5th wheel stability since installing the jacks is like night and day.
2. Front jacks are considerably faster, more so going from auto level to hitch and go. In my opinion you'd be happier with this setup, not just doing front jacks.
3. Removal of front jacks was easy. Shocking how cheap they're made. The gc 3.0 landing jacks are super heavy duty and well built. It will take two to install. The only issue I ran into was the mounting tabs on the trailer had to be cut down about 1/4" inch to get the jack to fit all the way back into the brackets. It was time consuming, but doable. I didn't have to rotate any motors.
My over all install was pretty straight forward. I did plenty of research and planning before purchasing. I'm so happy I went this route and I'm sure momma will be happier now that I won't be yelling at her like I did during our past leveling escapades...lol