@JoeR - there are many species in Malpighia, and a few species have several cultivars. Some are used more for their flowers, some for their fruit. The one raised for culinary fruit production has somewhat larger leaves than yours, more like the photo Anthony posted. There is a Malpighia with leaves like a miniature holly bush, called Singapore Holly, where it is popular as a landscape & potted plant for its flowers, not for its fruit. It is widely grown in Singapore and Malaysia.
You are in North Carolina, its winter, Malpighia is fairly tropical in habits, growing best when temperatures are well above 60 F at night and 15 F or more degrees warmer during the day. In cooler weather they may grow some, as your photo shows, but they are not growing vigorously, they are really semi-dormant. I would hold off on major repotting, & pruning until you can put it outside for the summer. You want your daytime highs above 80 F to get vigorous growth rolling.
While in the winter "doldrums", they don't need much fertilizer, hence the advice for 1/3rd strength. When the tree is growing rapidly, you can up either the amount of fertilizer, or increase the frequency with which you apply the fertilizer, which ever is your preference. Active growth they need more fertilizer.
If this tree was mine, I would not do anything now, then before thinking about pruning I would repot it much lower in the pot, so at least half or more of those exposed roots are covered. This is in part personal taste, I dislike 90% of the trees shown with exposed roots, My feeling is only the top half of the highest roots should be above the soil line. For most deciduous designs you should not be able to see what the diameter of a root is, only the top side should be visible. This is in part personal taste, not really a cultivation necessity. I would seat it lower, then give it 2 months or more to settle in. At the repotting, you could also go into a larger shallow pot, for more rapid growth with the intention of going back to a smaller pot after you get the back budding and branch development you want. Maybe a couple years or more in a larger pot.
When growth picks up and every branch end is growing, only then would I chop back the branches to try to force back budding. But don't do that until it has added some significant extension to the branches, at least 6 or so sets of leaves. You need the tree to build strength, so when you chop back, there is stored energy to feed the back buds. If you chop back too soon, it will only have enough energy for a lack luster back budding, and you won't have the choices you are hopping for.
This one has really nice bark, I like it. I have Eugenia, which is not related at all, but in many ways grows similarly. I think I will pick up a Malpighia someday, as I do like the bark you have on yours. Neat tree.
