Even with the restrictions, there are plenty of stunning places to fly legally in Oahu. See my post from last year in this thread (4/23/18) for a list of some places I found. And good flying!
If you are flying within the grid as a recreational pilot you have to call ATC and inform them of your intentions... these LAANC are for PT 107 pilots where we can submit a flight plan and get instant approval...
The LAANC map is a good indication of the altitudes you MUST adhere to whether PT 107 or Rec...