The above could be done now. This is a young tree and can endure a lot of BS without even skipping a beat. Lets see how things are going; we may consider a repot into a pond basket by August. I don't believe we have ever discussed how large you would like this tree to become. That would be a good discussion to have at about this time when we are going to be discussing the removal of branches.
Personally I think maybe adding 2 more inches in height would be the maximum size of this tree. Not quite a shohin, but fairly small. It currently stands at about 6" from the base to the top most tip, not taking into consideration the needle length. I would like to, obviously, thicken up the main trunks as well, and am considering leaving it as a twin trunk....
I didn't remove any growth, as I was under the impression that no pruning should be done before July 1st or so. With that said, I think that at the very least the bottom most little shoot in pic 3, should stay, and possible anything above it should be removed, to help with the taper issue.
Could I go ahead and prune back now due to the virility of the tree, or would you recommend just dealing with the circling root issue and fresh growth (pic 3) removal at this time. If only the roots and fresh growth get tackled this time around, do you reckon an additional branch pruning can be done further on in the summer?
I do have a couple fairly large pond baskets on stand by. I'd be happy to repot it in August, although, similar to your climate, it does start cooling come september, and so I would like it to have enough time to harden off before the cold snaps start hitting in the fall.
Thanks very much for your insights. I'm learning a great deal though this.