I don't have any new documenary information on your specific topic, but I'm still around and don't mean to ignore your message.
There is now a Hul*n* project attempting to sort out some of our lines via Y-DNA; but so far there are few participants, and we haven't been able to do much sorting. It may become useful after more bearers of the surname, however spelled (Hulan, Hulin, Hulen, Hulon, Huling, Hewling, among many) get tested at FTDNA (or, where possible, transfer in their results if they have been tested elsewhere).
It's clear that several families of the name are unrelated to each other within the United States and Canada; but some of them could have been related in Europe, within historical time. At this early stage we have no DNA evidence that proves or disproves that. Those of us who started the project are from NC/VA ancestral lines -- not the DE/PA (Swedish), Marblehead, or Canadian lines. The surname is a little unusual, and could represent several colonizations (and not just in North America) from a fairly remote time.