chipping latex paint on fireplace tile surround

Built a deck for a neighbor 12 years ago. House has been through 3 owners since. The deck saw little maintenance and the wood was quite weathered by the time the current owner contacted me last year for assistance. 11 years ago it received 1 coat of Thompsons Waterseal applied by owner #1. Since then, there has been zero maintenance done on the deck. I came in, replaced 1500 screws that had rusted out (homeowner screwed the boards down to save money - obviously used wrong type of screws), Replaced damaged boards, Power washed the deck rather aggressively, let dry, sanded the whole deck with a belt sander and a course grit paper. Then we coated it in a solid color stain of the premium variety from a box store (slap my hands). After one year, here is what the deck looks like after relatively light use. [ATTACH]84180[/ATTACH] Give me some suggestions - this is an warranty claim and I am out of pocket on the repair. I hired a buddy who is a lifelong painter to put the stain on as I was busy at the time. So I can't really answer any questions on application. Do I roll on another coat and hope for the best? The wood soaked it up pretty well as I had to buy a ton of extra stain at the time. Do I hit the voids with a semi-transparent in the hopes of the stain penetrating the wood and then over that put another coat of solid? Hope to not have to do this out of pocket each year. I also want a happy neighbor.

What is the proper way to dispose spay paint cans? I got two boxes of them. Some are not empty. I went to paintcare.org and searched for locations. But most of them do not accept spray cans.