As for pruning a young kousa to shape it up, follow the basic rules I’ve outlined on the blog (take out dead, damaged, diseased, as well as suckers at the base and also those shoots that are at odd angles that cannot become productive parts of the tree. That last group includes vertical sprouts off another branch, inward-facing/crossed shoots, ones that are so tight up against others that they cannot both make it. This video about a young kousa that I found explains these steps: http://www.tlcfortrees.info/specialty_tree_pruning.htm As for your crispy leaves, plants get tip burn when they are stressed from transplanting or from uneven soil-moisture or from other environmental stressors. Life in a container on a desk is stressful. How big is the pot? Kousas (except a few varieties) are quite large, and cannot optimally grow this way without complaining (i.e., showing you signs of stress). More details needed please on soil volume it has to grow in.