Root prune prairie fire crab apple tree(potted container)

[William climb safely]

Thank you to all that reply.
Mothers day is here and I purchased 2 trees one above and crimson (maple)
When I removed crab(12 ft tall) I was surprised to see all the circling roots.No pictures wife was impatient and wanted to see it in the ground .
I googled it though I knew this was the place to go but no time.I got the ones at top and the bottom.The ball was tight so didn't want to break or cut deep into middle.There was a spot in the middle of ball that had 3 to 4 roots(about 1/4 to little bigger) I couldn't tell where it started and ended went around and back in the ball.
I planted(wife thought I was killing it already)
Im thinking I need to dig up and fix depending on feedback.(2nd day in ground)I can send pics if I dig up.
Other question
Why would the nursery prune this crimson maple the way they did.White tape pic is central leader(seems they chose wrong one to prune) There was a hand full of branches it was like they topped the tree.All the trees were pruned this way.This was my best choice.
Im planting where a previous tree was and cleaning out the roots( fun)Should I remove all and how deep should should I clean.If the roots are same as crab Ill send pics if in bad shape before I plant.
Thank you so for your knowledge!

 

[Slicksty6]

Any roots that are not radial to the trunk are subject to removal to prevent girdling. Some advocate a complete pruning of all roots on the outside of the root ball on container trees.
The white tape is to train a new main stem to be straight after they cut off its codominant twin next to it. It will be fine.

 

[ATH]

Here is what Ed Gilman has to say about it. I'd venture a bet he has done more research than anybody on the matter:

https://hort.ifas.ufl.edu/woody/shave-prune.shtml

 

[William climb safely]

Any roots that are not radial to the trunk are subject to removal to prevent girdling. Some advocate a complete pruning of all roots on the outside of the root ball on container trees.
The white tape is to train a new main stem to be straight after they cut off its codominant twin next to it. It will be fine.

Thank you

 

[William climb safely]

Here is what Ed Gilman has to say about it. I'd venture a bet he has done more research than anybody on the matter:

https://hort.ifas.ufl.edu/woody/shave-prune.shtml

Thank you