Help with wildflower IDs

#1

Closer shot

Leaves

#2 Top view.

Side view

#3

#4 I believe this is Salvia azurea but how do I tell the difference between azurea and azurea var grandiflora?

# 1 I would have said a Bush Sunflower, but the leaves you showed don't match, although the leaves on the first picture seem to match.
http://wildflower.org/plants/result.php?id_plant=SICA7
Or maybe a type of Coreopsis.

#2 is one of the Ironweeds,

#3 I have no idea

#4 I guess the flowers are larger.

Well I have narrowed it down a bit. #1 I believe is Swamp Sunflower, Helianthus angustifolius.
#3 is some type of Lobelia, possible Downy Lobelia, Lobelia puberula.

They are all very pretty.