This is one of those unexpected buys. I am not much into Magnolia actually. They grow slow, do not flower in enough numbers (at least the ones in my office) and take like forever for the flowers to develop. But when the local Nursery had them marked down I could not resist picking one up. Just for the sheer pleasure of planting one in a pot. I know. Perverse. Lol. As usual this also goes in 511 mix. I am thinking about pot size. Should I start with a pot size one level big compared to what it is in right now? Or as people say, put it in a big pot. It is winters and I fail to understand how they made it put out new leaves. And there is a bud also on the lower right one. Anyways, I like bushy plants. And this guy is spindly. So will this guy die if I remove the main trunk at the level where green bands are located? I know its a slow grower which is fine with me. But will it bud out from the main trunk? I am hoping it will bud out from the main trunk left and will grow many branches out of it. Or will it just die? Or will the lower two branches just take off and leave the middle one as it is? If the experts say yes to reduce the main trunk to half the size then what is right time to prune? Or should I remove the lower branches and hope the top crown flushes out into a nice top heavy tree? And any tips and tricks? To make life more interesting?

Benefit of root pruning in preparation for transplanting as a general practice remains questionable. Of course, when growers do it to make root systems of field stock smaller, more easily dug therefore it certainly has that effect. Otherwise probably much of the time - in various situations - the branching produced by cutting the roots well in advance is nullified during the digging of the specimen by it being cut back to the same point where the advance pruning was done. I moved a small (3' or less) deciduous magnolia once during August, it did great afterward. Because top growth was mature already, roots were not cut so it made a bunch of fall root elongation right after re-planting. Perfect!

Way too hot to transplant now. If you can put shade cloth (or an umbrella) over, that will help, but in our climate (and you are considerably hotter than I am) transplanting woody plants is best done in late fall/winter. This is just due to the heat and long days. Shade and water may allow them to limp through, but since they are not going to regrow those burned leaves, even if they survive, you may have to wait a whle for them to look decent.

IMO, your new tree looks fine. Maybe just a bit of slight transplant shock and some physiological damage from handling, transporting and planting but nothing serious or with a need to resolve. I would caution about relying just on rainfall for watering new plantings. It is rarely sufficient to provide enough moisture at depth, so you will need to check periodically to see how moist the soil surrounding the rootball and the rootball itself may be. And always water in thoroughly after planting. As long as you know that evergreen magnolias are hardy for your location, we don't need to know zone or large city or anything else :-)) The new planting aftercare will be the same regardless.