Your reaction to pruning is common. Folks tend to think of pruning as being like surgery or amputation. A better analogy is that pruning is like getting a haircut. Pruning will affect the overall shape and size of the plant, but it will not affect the health of the plant in any way. Thus, it is not something to fear. The worst that can happen is that you prune off too much, but it will grow back.
Yours is not in need of pruning at this point, but it will be in the future, maybe in a year or so. By then, more of the older leaves will have dropped off and the individual stems will have grown taller and longer while adding new leaves at the ends of each stem. After a while, it will have what is commonly called a "leggy" appearance with many long stems that are bare on their lower portions. It is those stems that are candidates for pruning as a way to eliminate the bare stems and to promote healthy new growth lower down on the stems.
It is hard to be specific because your Aralia does not yet need pruning. Do keep it in mind and come back in a year or so for more advice specific to your plant. In the interim focus on providing good light and proper watering. And avoid repotting and over-fertilizing it .
