Kesusu sometimes refereed as close relative to artocarpus family, so no surprise taste and texture similar to some sweet artocarpus. At first you only taste sweet. Sour kick comes 1-2 seconds later. Imagine very soft jackfruit or chempedak, than add berry twist with a dash of cranberry sourness. I hope this will help your imagination juices flowing
Yes, you are right, no exterior peal. Just an ultra thin skin. You can get sense of that skin looking at my photo of wrinkles on exterior. Entire fruit is exposed out in the open. I felt a little bit uneasy eating it, because you don't know what was landing on those fruits. I did not see any bird damage.
Despite being perhaps most exotic looking fruit in the world, I think it has very limited commercial potential even for a farmers market, because arils separate from the core quite easily. Basically you have to cut it from the tree and hold it by the stem to make it presentable. Stacking one on another will ruin them. You will just end up holding arils in you hand, like I do in the photo. It does not mean I'm down on the tree. Actually would like to plant two more.