You can use the hooks and there is no great problem, however, there is the potential for the tape knot to come off the hook. Unlikely but still a risk.
The reason the hammock is hung by tieing the tapes to the tree THEN adjusting the hieght by tieing a knot at the rings is so that you can make the adjustmentds to the hammock hieght under the cover of the tarp. So you can have it set high for sleeping and then adjustt it to a lower position for sitting on during the day, without getting wet. It is also much quicker and simpler than trying to re do the knot at the tree. there is also the advantage that the loops of spare tape hanging at the rings act as drip lines and stop any water working its way along the tapes from getting to the hammock itself.