Most important thing to know.... they will not backbud on old wood... You have to use what's there.... So the chopping of the tree and pruning back the legginess of it, is on your order of business. If you have a lot of bare branch you can always use some pretty creative movement to get it back where it needs to be. As with most conifers, I wouldn't bare root it completely, but you can get pretty heavy handed with reducing them by halves. They will thrive in pumice/composted bark/akadama... and they really love getting some iron in their feedings. I actually just put Ironite on my larger ones and let them go. You can get it at Lowes here. It would even be a good thing to do now until it goes fully dormant.
I wouldn't wait a year and a half to start getting it out of that soil. It's likely an Oregon clay, and that's a miserable medium under the best of circumstances. If it were mine, I would get it out of the can in the spring, take off a good section of the bottom and wash down the top to see your nebari, wedge it here and there... and put it in a grow box with some nice pumice.... pure pumice at that, for this stage.
Also considering what you want to leave... you'd do fine to get that chop done, just leave several inches from where you want to ultimately be. Doing it in late fall when the tree is drawn down, will be the best time... paste or not as you prefer.
I understand the caution... and generally there's everything good in that plan.. but a chop and a root ball reduction will not hurt this tree.... not wasting energy where you don't need it will also not hurt this tree. I would just wait on the heavy pruning that ultimately needs to happen.
Kindly,
Victrinia