I am not an expert, but it is probably energy related in the size of the leaves, didn't have much after you dug it out, but it will regain over time, looks good! Nice tree, enjoy!
And those small leaves in this situation says, leave me alone for year.
Exactly. I was about to make both of these points!
In terms of your other question about "
If I cut all limbs but top one will top one thicken and look natural instaed of like a cut off tree?" I would say "no", generally not. However if you think like Mother Nature, you will come up with a solution. Assume your tree was 100x as large, and was growing in a field, and then another tree fell on it and broke off the top 50% of the tree. What would it look like? What would happen? In general, the first thing is that the break wouldn't look like a saw cut, but would be ragged and raw, and the margins of the injury wouldn't be perfectly symmetrical. Then the second thing that would happen would be that the margins of the injury would seal off the wound, while the exposed deadwood would age and weather, and might rot away entirely.
So when I look at your tree I see a tree with a hollow trunk and a shari running down the side, and live growth only on one side of the trunk. Hollowing the trunk and creating a shari will also allow you to add visual taper so the trunk doesn't look like a straight pipe. But do NOT do this work now. Let the tree rest and recover and grow strong first. Then perhaps next year you can practice your carving skills!
