Gosh, I would be a little less concerned about getting the neg feedback removed, and instead sit down and read the ebay Policy  - on feedback if nothing else. You aren't allowed to leave an unrelated to transaction feedback comment - besides, it looks shocking!

As to your original post - i actually prefer p.o. boxes to street addresses. PO Boxes dont have sticky fingered posties or neighbours, or incorrect numbers or the like.

In the time I have been selling I have had at least 6 to 8 parcels each year go stray, but only ever had one to a po box (last month) - and it was one of those "Town X via Town Y" ones.