Don't prune anything flush on a Raintree. They have a tendency to die-back. I don't use concave cutters, just scissors. If your pruning a branch to the trunk, leave a stump. Once that has died off you can clean up the stump. There will be a little bump there, it will add to the character of the trunk. When pruning a branch along it's length, leave a substantial amount of space between your cut and the lower bud. If you don't, it will die-back down to the next bud. Trust me, your not feeding enough. Looks like you have some Osmocote on there, I would double what you have on there!! I use Miracle-grow tomato food in addition to granular feed and fish and seaweed emulsion. Since you have it outside already, I would start feeding weekly or every two weeks.
Full sun, loves to eat and drink. These are really resilient trees so don't worry too much about it's travels. They adapt very quickly to their environment. Yours looks fine, leaves are a little pale but looks healthy. You should have some long shoots before you know it!! Just stay on the top growth hard or your lower branches will get shaded out and lose vigor . They can back bud on a branch, but you will have a tough time with getting new buds on the trunk.
One more thing. I don't do the "spring two-step with tropicals, particularly Raintrees. Not a lot of benefits, too much environmental changes. I stage tropicals where I house my cold-hardy plants in the winter to acclimate to the light and outdoor conditions One time out in spring and then when it's time to go indoors, late summer, early fall, that's it. My Raintree will drop leaves coming outdoors in spring and again when it goes back indoors. Wait until you see plump green buds at the base of each set of leaves from the previous growing cycle. That way, when it sheds leaves, you have new buds ready to take over.
You should cut back all that top growth.
