I am pretty confident. The 4th photo (of the face) especially looks like a Pine Warbler. Yellow-throated Vireos not only have larger bills, they have larger eyes and a more contrasting face pattern. Your bird also appears to have orange feet which rules out vireos (which have blue feet).
I can't really say how many we see on average. We see a lot more raptors during the spring, fall, and winter months. In the summer we maybe see one raptor (mainly Red-tailed, Broad-winged, or Cooper's) every other day.
#2 is a Lincoln's Sparrow (gray base color on face, buffy malar, thin streaking on buffy breast and flanks, raised crest). I'll let others ID the first since I have no experience with Brewer's.
I think @scall0way is right - one Canada, one domestic Swan Goose (with some domestic Graylag in it), and three domestic Swan/Graylag X Canada Geese hybrids.
The OP's bird is definitely a Chipping Sparrow. American Tree Sparrows have yellow lower mandibles, rufous eyelines, and buffy flanks (and it would be very unusual to see one in the lower 48 in the summer).