Well part of learning is keeping a tree alive, it nursing said tree back to health. Ill do as you recommend and hope for back budding. Why only remove 2/3 of the old soil come spring? My plan is to build a nice large growbox for it. Its sad looking though....a many plants are at this nursery...overgrown, overtaken, and over watered..also can i assume a 60 percent grit mix like a pine?
For the most part, you really don't want to bare root conifers. Some, such as yew, in certain conditions, can be bare rooted. Also, this tree is not in great health, removing all it's soil is not a good idea. If the tree does well, in 2-3 years, then you can remove whats left of the old soil. At which point, you will have mostly fresh soil. Just make sure that althought some old soil is left, that is is not cememented or blocking drainage in that area.
Lastly and this is going to save you time, money and anguish..lol..Try to start with healthy material. The reasons are endless for this. Here are just a couple. Being new to the art, the main pointss now are learning, doing and having fun. When you purchase an unhealthy tree, you really can't accomplish any of these. You won't be able to work on this tree for 2-3 years. Also, the tree may not be very receptive to work due to poor health. You could spend 2-3 years with this tree, pots, soil, time and then it might just end up dying. You could also give it the 2-3 years, then work on it and if it does not like it, you could lose it. Which means basically you baby sat a tree, started at it for years and in the end you lost it. Of course, there are exceptions. If you find a really nice specimen and it is recovering, then this might be a different story.
There is so much to to learn, but it is also fun. The journey is half the fun. With unhealthy stock, it negates these things.
Rob