Trees, Shrubs and Conifers: Urgent Answer Needed for Boxelder Question, 1 by Yellowbricks

Yellowbricks wrote:
We live In NC where tornadoes came through last week and did evil. I watched a 40 foot limb fall from an old boxelder in our backyard. The wind was not the only culprit as the tree was compromised unbeknownst to us.
Yesterday an arborist/treecutter came to advise us as to if the tree should come down or be pruned to eliminate the internally damaged area. He suggested the latter, which is scheduled for Friday, April 29. In fact he said that the diseased part of the tree had been caused by a pruning wound,which allowed some disease to set in. So he is very conservative about creating more pruning sites.
As much as I respect this point of view, my concern is that the tree has a very large and heavy limb directly over an outbuilding in the yard, which happens to house my studio. He did not recommend taking the limb down or even reducing it. In my brief research of boxelders, I have found that they are shortlived and prone to win damage. This limb is like a sword of Damocles over the place that contains all of the materials and tools of my trade. As one can imagine, arborists around here are very busy, what with all the damage Raleigh has sustained and so I thought I'd put this situation on the forum and see if anyone has experience with this type of tree and a viewpoint as to whether I should take the limb down or not.