First, I'll say that trees don't really dampen sound. It seems like they should, but I recall reading some research on the subject that concluded trees and shrub do not significantly dampen highway noise. However, a barrier is still nice, so you may want to go ahead with your plan. Is the barrier going to be planted in the open or in shade? In the open Eastern Red cedar, northern white cedar, or any of the shade trees below would work. in shade, Easern Hemlock, Balsam Fir, White Spruce would work. Any of these are native to your area, and when young are dense near ground level, making a nice screen.

I'd be surprised to find that you have to plant anything to attract deer. in general you should have plenty of deer as long as you have some areas of low growth, woodland edge, or shrubs. Deer might be scarce if you are in an area of primarily mature woods, where they don't find a lot to eat.

I would not try to remove any species of tree except if you have something non-native and potentially invasive on the property. If you are going to thin trees, I'd try to leave the better shaped or larger trees, and thin some of the smaller or crowded trees. I'd want to leave behind a mix of various species including some evergreens, and create some small openings. I'd also consider removing a few trees that might be shading stands of desirable shrubs. Many shrubs will produce berries for wildlife, brwose for deer, and cover for small animals, as well as add a lot of interest for you. once you get a handle on the types of shrubs that are growing there, you can perhaps remove a few trees to give the shrubs more sun.

If you are removing a few trees, consider girdling some and leaving them standing. Dead, standing trees support a great deal of wildlife, starting with woodpeckers then including many other birds and animals that move into the holes created by woodpeckers.

Are there any specific shrubs for this climate and soil (sandy) that you would recomend??

Suggestion for blocking noise. Plant the same as an effective windbreak by planting short plants/trees then on the inside trees that will grow taller. The angle will direct the noise to a certain extent. As far as your children plant something prickly and teach them what they should and should not do.

I like the suggestions above. Evergreens of various sorts will provide more year-round cover. Arborvitaes retain growth at low and high points if I remember correctly. Use native arborvitaes of course. They are commercially available. The main problem with arborvitaes is that they are so common that they have become kind of boring. Native hollies would also be good.

From what I understand, earth berms are the best way to block noise. If the expense isn't prohibitive, planting trees for screening on top of an earth berm for sound reduction might be the way to go.