Very nice pics, LP!
In the first set, the first two pics are definitely of one or more hairy woodpeckers. The third looks more like a downy, but it might just be the angle of the shot. You can tell the two apart by looking at the length of the bill in relation to the head. There are side-by-side pics of a downy vs a hairy on page 2 of this thread right at the top (post 31). Look at the length of the bill--see how the downy's is stubby? If you turned it around and poked it into its head (
), it wouldn't extend far into the head at all. The hairy woodpecker to the right has a proportionately longer beak--turn that one into the head and it would do serious brain damage.
(Although those pics make it look like a downy is bigger than a hairy, don't be fooled--it's just a fluke of the pics. A hairy is half-again as large as a downy, but they're so similar otherwise that unless you have something to compare them to, impression of size isn't a very good field mark.)
Anyway, your first, second and fourth shots are all definitely hairy woodpeckers. #3 could be either...I can't tell if the bill is actually that short or if the angle of the shot just makes it look that way. And it can be difficult to tell them from the back as shown in #5 unless you see them both there and know how big each is in comparison to the feeder. However, I can tell you that it's definitely a female in that last shot (females lack the red on the head) and from the posture, I'd guess it's a hairy.
9 woodpeckers in your woods? Cool! Ours are getting all feisty and chasing each other around the trees. Watch for pairs getting territorial--I've seen two pairs match up, male to male and fem to fem, dancing around the branches and trunks and making weird little throaty noises. I have no idea how they choose a winner, or what happens if the male of one couple wins his battle and the opposite fem wins hers...but they always seem to work it out to everyone's satisfaction in the end.