For the most part any marijuana plant can turn hermie by stress of one type or the other. Heat stress is the most common cause of a plant turning hermie.

Seeds from a hermie plant only carry the trait of hermie more promenade then seeds from a cross plant does. In other words there is no guarantee that a seed from a hermie plant will produce hermies. You need to correct the reason the plant turned hermie in the first place for the next round. So seeds from a hermie plant will not always produce hermies. They may be more sensitive to the trait but that's all.

I have had plenty of hermie plants in my time and yes I kept those seeds (just in case, to keep the strain around), those plants are not the ones you want to make crosses with but for smoke or super quality bag seed they are fine. They just are not #1 seeds that's all.