I noticed links coming from another site and viewed your post over there. The deck is very bad in some spots and those boards you can pull and replace but overall I have seen and salvaged worse.

Your plan of attack is sound.

1) Do your repairs first.
2) If you have to sand, do that second. Be sure to sink all of your nails before you use a floor sander. I honestly don't think you will need one and with the condition of some of those boards (even the good ones) you may end up with splintering or go through a ton of sanding pads.
3) Use the RAD System. I would recommend using a pressure washer to remove decayed wood fibers and sped the process. You could also use a medium bristle deck brush and a garden hose
4) Wait 4 days of dry weather.
5) Seal the deck with Ready Seal. The mineral oil in Ready Seal will soften the wood and make it more plesant to walk upon. You could actually eliminate much of the sanding using this type of parafinic oil.
6) I would add another coat of Ready Seal in two weeks to the floor. You can do this with Ready Seal because it does not cure and a second application will dive into the wood.

After the second coat I think you will be amazed at the transformation and with yearly maintenance you will easily get another five years from the deck.

Awesome advice, thanks!
You'll get my order today :D

Sorry I didn't think to ask linking permission, as a completely entrenched netizen, it doesn't occur to me, though I admit it's good practice.
If it helps you can consider it free advertising :)
(If it's killing your bandwidth let me know and I'll remove the link)

As to your suggestions:
Do you find the Powerwash broom to be effective? and would a 1300 psi washer be sufficient?
I've not seen RandySeal mentioned, is that an alternative to TPW stain or should I seal it, then stain it?

Thanks!

Additionally, where is Ready Seal available from?
I found their website and could order from there, but I'd like to check prices locally and hopefully save on shipping.

In order...

I should be thanking you. The more sites that link to mine the higher my search engine ranking climbs. I'll pay for a hundred times more bandwidth if it means increased hit rate.

Ready Seal is a contractor product that was developed to be fool proof in application and very easy to maintain (you never have to strip it) It trades off in a few areas like longevity which is why I mentioned upkep but the nice part is, upkeep is quick and simplified. Quick cleaning and throw down another coat. You don't have to mask rails and you can stain half and then go back and stain the orher half of the deck a week later and the two parts will blend. The color wil fade quickly but it is the best type of oil to remoisturize the deck. Next spring I will be introducing Wood Rich wil be compatible with products that contain parafinic oil and the Wood Rich will seal in that moisture and keep its color for three years.

Any advice on removing deck screws from the old boards? I spent about a 1/2 hour on one 8' board last night and it was a miserable experience. I could only remove one screw intact.
They're phillips and extremely rusted. The heads are rusted and strip easily, the shafts are fragile and break and in some cases the wood fibers have covered the head.

On the last few, I took a screwdriver and hammer and tried to clear out the debris from the head and give myself a little purchase which worked but the whole thing just sucks.

I see that there are some damaged screw extractors on amazon and elsewhere... anybody use these with success?

Thanks!

How do we purchase Ready Seal? Any contacts in Washington state? Thanks.