Thanks for your suggested advice on how to proceed...I've not even slip potted it. It's in the pot it arrived in. I just added bonsai substrate to this pot that does have a hole in the bottom. To hide the black plastic trimmed down nursery pot. The substrate around pot is fast draining...but would imagine it would not effect the roots or watering overly. Just a light skim coat of it over the surface of what was already in the pot. Thus...Pulling it out of this planter...and dumping out the substrate...sitting down gallon nursery pot in at an angle alightly trimming the nursery pot on the left side...and filling with substrate was all I did. Not touching anything of the soil what so ever,nor touching or messing with the roots...nor cutting anything on the tree. As I was advised to see how healthy it budded out. When it budded out weird...It concerned me. Not doing anything but offering horticultural care until it appears to bud out more evenly hopefully next spring.
Tree does not seem to be growing well to me. My experience with Amur Maple is they are rapid growing trees with beautiful, graceful foliage. They can take a beating and be fine, but n tree can survive rough conditions forever... And certain characteristics vary among different types of trees.
This is your issue IMO- you have a tree where over half the existing trunk is dead. A tree that does not tend to adapt well to dead wood, and is growing in a pot it is clearly not doing well in. Maples are not like Juniper where a run of deadwood will just be grown around and the live veins are completely separated from the hard, bleached old deadwood... A Maple has dead wood and it lets it rot, fall off then covers the scar over.. So, you are kind of working against the way this tree grows. A little deadwood here or there might not cause any issues... But THIS much... On a tree this small...? Let's just say it is fortunate to be alive at all.
I think what M5 is saying here and what I'd say too is- let's get this tree BOOMING with new growth before insulting it in any way! Do whatever is necessary to encourage LOTS AND LOTS OF GROWTH! Let's get this guy super vigorous and happy before a major rework is done/ before any style concerns are addressed. After all dead trees are really really hard to style!
If it was mine I'd drop it in the ground. Let it grow wild for a year or two... If it covers over some deadwood, great/ fine! Might make a better tree! The goal is to get it real healthy and real happy and showing a lot of healthy growth low on the trunk before any attempts to restyle, cut back or change angles... Once it shows you it is happy, take it out of the ground, and get on the roots and branches HARD! Maples like a good root work over from time to time when being kept in pots...movies them room to grow the roots and that leads to lots of top grow the and a Maple pushing lots of growth is a happy tree! Happy trees are vital to bonsai!
Good luck, hope it works out well!
