Chickadee is a good word. Of course we in in the USA would blush to use that other word! We had the black-capped type on the Vineyard, bold little guys, you could almost hand feed them. I have not seen many here, but I do hear them.

The grackles are so pretty, black with shining purple and blue in it, and a fancy pattern of speckles. And they travel in huge groups, thousands. Sometimes you will see a tree, and it looks perfectly ordinary, and then as you get closer it is all in motion, and it was full of birds and you didn't even know, and they just lift away and what you thought was tree was mostly birds after all. I love when that happens. It happens a lot with grackles.

Purple finches are more sort of a dull maroon, verging on brown. Brooklyn is well supplied with them. They are not as shy as some of the other birds, so despite being small they bellied right up to the feeder. I tried to get a mix of suet and seed that would please a variety of birds. Not sure how well I did with that, but the finches here are seed guys. As far as I can tell chickadees eat berries, and nuts and seeds. They have sort of an all purpose beak.

Grackles eat bugs I think, they seem to like the suet ok.

Yes, grackles look like small shining crows. They are not crow family though, not corvids. But blue jays are, which just goes to show something I suppose.