New pressure-treated pine deck - advice on surface prep

Hello,

I am in western North Carolina, and had my deck surface, railings, and stairs redone in new pressure-treated pine in October of 2014. I plan to stain this March (and hopefully avoid the first wave of pollen). It is a raised deck - off the back of the house on a slope, making it essentially a second story deck with the basement below.

I will use Armstrong Clark semi-transparent stain, and similar to this forum, Jack Clark recommends a wood brightener prior to staining.

It is now late January, and the wood has dried out quite a bit, with some cracks and splinters here and there. Also, the screws are countersunk, with many small splinters around the screw holes. I would like to lightly sand the imperfections away with a 60 or 80 grit using a (hand) orbital sander, at least for the rail and deck surfaces. I would plan to do this soon, and then wait ~6 weeks prior to staining.

I have read quite a bit on this forum, including:

DECKSTAINHELP.COM "http://www.deckstainhelp.com/staining-a-new-deck/"

How to Stain a Brand New Deck: Best Way to Stain a New Deck

So you have a brand new deck and now it needs to be stained. We will teach you how to stain a new wood deck and how to prep a new deck for staining.

Most of what I read advises owners not to sand prior to staining. Is a rough sand to remove splinters/etc discouraged? If so, what alternatives are there?

Also, given that it is a raised deck, I will also stain the posts and framing - would sanding these remove the aged, gray wood and get me closer to a similar stain as the new wood? The frame is close to 10 years old, and while in good structural condition, was never stained and therefore quite gray. I also replaced a crooked post to add an additional variable to uneven staining...

I realize these are simple questions, but I'd like to get it right the first time and this seems like the audience to ask. I'd hate to mess up what is currently a beautiful deck.