One way to attack the humps is a plane old electric iron. It will melt the humps away in pretty good time. I've used a propane torch from home depot. It takes a lot of time to reduce the bumps. The iron method is a lot more efficient. The only problem is that the neighbors will think you are crazy b...

we have a walkout, so I store the board under my deck next to my shed. I just wrap them up in some of the old plastic liner. No issues with water, etc. Done this for about 5 years now.