As far as your deck goes my advice is to oil stain it. Paint will peal and chip and really hard to do a nice job when you have to recoat. All the deck stains I’ve seen are semi transparent paints same problem with recoat. Get enough linseed oil and pure stain of your choosing mix and slop it on. It will soak in, shows wood grain and age beautifully, recoat no prob, no scraping, no power washing, scrubbing etc. just make sure it’s good and dry then slop it on. You won’t be able to use your deck for a couple of days till the oil soaks in. But protected looks good and easy to apply. Wouldn’t use anything else on my deck