Will negative GMP and positive online GMP still hurt morale?

Solution 1:

The online resources can be viewed as a sort of "savings fund".

It seems that you are given a set amount that you can keep offline at a time and once this set amount drops to zero it will transfer more to you the next time you connect to the servers or hit checkpoints in or between missions.

So when your offline resources drop and there is no more online resources to feed in, that is when the staff moral will drop.

If your offline resources are negative but your online positive, some online resources should get transferred over.