I don't think insulating a pot will do much good unless there is a heat source inside the insulation. Insulation slows the transfer of heat from something warm to something cold. Thus if the pot is warm and the air cools, insulation would help slow down the cooling of the pot. However, without a source of heat in the pot, eventually the pot will cool to the surrounding air temperature. If you had a few cold nights to worry about, perhaps the insulation would keep the soil in the pot from ever reaching the air temperature, but it won't keep the pot warm through a long NH winter. insulation would help slow the rate of temperature change in the pot, which I am sure would be good for the roots, but you still might end up with dead plants due to excessively cold roots. i would plant the trees in the ground. Lots of fruit orchards exist on fairly bad soils, so I think your spot will be fine. I find most things, especially long-lived things like trees, are a lot easier to grow in the ground than in a pot.

Well, raised beds aren't really container gardening because the plants roots can penetrate into the ground. A container is closed at the bottom. Raised beds are very good if you have poor drainage. You can grow any tree in a raised bed, a lot of people just make a mound instead because it's easier. A lot of the plants you want should be in containers because of your zone (5a). Citrus, Tropicals, Sub Tropicals will have to be brought inside for the winter. From your list I would stick with just apple, pear, and peach for raised beds. The other ones need to be containers for your zone. Bare Root means the tree is dormant (no leaves, no growing), kind of a hibernation period. They are shipped without any soil. It will look like a dead stick with roots at the bottom when you get it.

I will try to grow just about anything. I have plenty in the ground and way too much in pots that I drag around the yard during the summer and shove into a makeshift greenhouse for the winter. February marks my second year in this new house (which is actually an older house) so a lot of what I have is still too young to fruit. Even things that normally were not my favorite flavor ended up growing on me so now I can't imagine gardening without them (guavas come to mind). I guess the oddest thing in the ground is my Arbequenia Olive which is planted right up against the brick wall of the house and doing just fine. They are rated zone 8 and I am a warm zone 7b. In its entire life (most of which was in a pot) it has only made ONE tiny olive that made it all the way to maturity. I joke that I could have squeezed one drop of oil onto one tiny crouton with that crop. This year's lack of winter is making what looks like bumper crop of Loquats - we'll see. They don't ripen til April. I have the best luck with the small pomegranate sold by Plant Delights as 'State Fair'. It is a small bush with half sized fruits that are more brown than red but the flavor is great and the bush is very very very prolific. It pretty much blooms from early spring til December and sets more fruit than you can pick. It even self sows, the ground under it is covered with babies. I have good luck (sort of) with the bush cherry series: Jan, Joel, and Joy. The bushes are way cute when in bloom but they do catch every plum disease out there and the fruit is often disfigured. But right about when you think they should be starting to rot is when they finally taste like regular cherries - otherwise they taste more like wild plums. Some people don't like the flavor of Goumi's but I flat out love them and plan on growing an entire row of them this year. Sweet Scarlet is very prolific but Red Gem has better flavor (with only a fifth of the fruit). They taste kinda like a cranberry and more berry like than their cousin Autumn Olive which is highly invasive. Years ago I stumbled upon a very tasty form of native passionvine. I have allowed it to escape into my yard and so far it has behaved. The fruit is nasty looking but tastes like Hawai'i to me. It makes a great smoothie mixed with orange juice and guava. I have European pears which do fine but lack any great flavor. I have two Asian Pears but only one of them has produced so far and the raccoons got all the fruit. I have apples which do ok - I haven't sprayed in the past and the fruit really suffered. I have peaches but they didn't care for the high heat and drought of the past two summers. I have no problem growing raspberries and blackberries and elderberries. I am growing but so far have not gotten any fruit from: fuzzy kiwi, hardy kiwi, pawpaw, wineberry, pineapple guava, service berry, cornelian cherry, shippova, quince, che, medlar, mulberry. I've already ordered sea buckthorn, aronia and honeyberry to plant this year (they should show up in early April). The greenhouse is full but worth all the hassles to keep it warm - guavas all fall and citrus all winter - yum.

Toni, I don't think there will be any problems with the trees when they mature. I have a few peach trees that were planted "3 in a hole" and they continue to do well year after year. The bed has 18 trees and is about 25 feet long and about 6 feet wide. I keep the greenhouse at 60 degrees minimum so I can grow many tropicals from fruit trees like Sugar Apples, Soursop and Jakfruit to flowering plants like Heliconia and Ginger. These plants are growing right in the ground, not in pots. There is no real "floor".