Wondering if I can cut this branch off of this tree.
You can prune the limb from the maple tree. See our publication for proper pruning practices. Do not leave a stub. http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG84_Pruning%20ornam...
We notice that the tree looks like it may be planted too deeply and/or there is quite a bit of mulch piled around the trunk. You should be able to see the flare of the trunk at the base. Make sure mulch is no thicker than two inches and keep away from the base of the trunk.