If you're okay with it, let's start with the pines first and maybe get to the others later:
Are these trees part of a "woods" or your lawn?
Do you think these pines were planted, or natural regeneration?
Do any of your pines have an orange-ish color on the trunk up 20 or 30 feet?
Is the main stem/trunk on your pine trees straight-up and true, or kinda "scraggly"? If that makes any sense....
I had to look up 3-Needle pines...there's a few - Pitch pine is one in the northeast with a shorter needle.
Now 2-needle, there's a few with short (2" - often twisted) needles that are prone to nematodes. Jack and Scots are 2 that some to mind - they both have twisted needles that are pretty stiff. Jack is local to you I think, Scots are from over the pond. Jack Pine is what used to make up the Pine Barrens in New Jersey. They really like periodic fires to help them regenerate.
Red Pines also have 2 needles; they're 6-8" or so and stiff and rough. They are also prone to nematode problems, I think.
Eastern White Pine has 5 needles, maybe 3-4" and the needles are thin and soft to the touch. Nice tree and quite hardy. They do have some insect problems.
Just a thought, Pines don't like shade. They need full sun, and don't tolerate shade at all. If they're being overgrown/shaded by other trees, they will decline quickly.
Another possibility - - Some pines are noted for deep "tap" roots - - think a carrot. Do best in sandy soil. Around here, a lot of Red Pine and other species, including Jack and Scots, were planted in clay soil. They'll do well for 60 years, then "hit the wall" and fall apart due to soil conditions. I sold 3,000 tons of a small Red Pine clear cut a few years ago. If it was sold 15 years ago, bet I'd have sold 4,500 tons...
Just guessing, but your Tamarack and Hemlock look good because they grew up there from seed. They're (almost) bulletproof when they grow up to maturity by themselves...
It's much less sustainable for the tree seedling when people decide "this is a good spot for this tree..."