Fixing Incorrect Concrete Leveler Application
You really should remove the stuff that was mixed overly wet - that tends to make cement products very weak. As a result, it should be easy to remove - might even come out with a stiff broom, if not, stiff wire brush might well do it.

Check the labelling on your paint - in most cases you should wait at least 30 days before painting (or attempting to paint) any fresh concrete product.