[Sticky] Properly Cleaning a Deck Before Staining

@bobr You can go ahead and stain as you removed most of it.

I live in east Tennessee...crazy unpredictable weather & humidity. The part of my parents deck I'm working on is 5-10yr old pressure treated pine...full sun from sun up until sun down. Past treatment has been yearly pressure washing then Thompson's water seal. This year I've been researching online until my brain is mush! I used an electric pressure washer (water only)...then used Deck Restoration Plus cleaner and Deck Restoration Plus brightener. I've already purchased 6 gallons of Ready Seal Pecan stain...roller, pad, deck brush, moisture meter. After brightener it began raining for a week straight and currently it's been raining every 2 days. I'm in my 60's and have never tackled anything like this and thought Ready Seal would be easier on me...both physically and financially. They say not to sand before sanding but I have white fuzziness all over. I get conflicted information online about sanding...even the order in which to clean and sand.
It's been almost a month since I started this whole process and it's wearing me out. Should I sand the fuzziness (80 grind orbital hand sander) and if I do...do I need to clean & brighten again and how long to wait after sanding? If I don't need to sand...do I need to clean & brighten again due to how long it's been or do to anything you see in the pictures? Any help/advice would be greatly appreciated!!