We've had this discussion here before. In fact, the exact same one.
The use of 4hi will only bind and cause understeer during sharp turns where the differential does not have time to keep up. Under normal road driving "binding" is virtually non existant. If it did exist, you would not be able to get the case out of 4hi after using it on a dry surface.
Like when Denise tried to remove the ZJ from 4hi last month, when she had 456 gear in the front, and 355's in the rear. Not fun.
As for whether or not you drive in 4wd or 2wd when the roads are bad, honestly, who cares. Its your decision to do whatever you are comfortable with, or what ever makes you more comfortable when on the bad roads.
Just so long as everyone understands there is no additional risk or wear and tear above normal if you decide to drive to and from work using 4hi.