This is an interesting thread and utube video. Per video- Power to the Green Revolution. Neem won a global trial. S-H thanks for directing this article my way. Nice to see what a neem tree looks like. So much to learn and understand about neem trees. Now is a good time to search for neem tree seedlings. Unfortunately in zone 8 they are not cold hardy enough, would luv to add it to my tree collection. Sounds very beneficial and beautiful. I could try to keep a neem tree in a large pot and bring inside during winter. Just a thought.
Yes, I think you can keep it in a big container, (with caster wheels) - And sure, you can bring it inside during winter. However the easier solution would be to build a climate controled greenhouse around it. So it can grow big.
I have used neem oil a lot for fungus diseases and i sects in my garden. One needs to be careful - I've caused leaf burn on seedlings and roses. But it does do a great job most of the time, and is natural.
You must be using it in too high a concentration. So dilute it by 50% and see if the leaf burn stops.