put up a little rail with slats on both ends for balance that should do

The best way to hide something outside is with plants. You could also use a low/small decorative screen with the plants.

Is anyone handy in your household? A very tall planter box sized for that area would be great. Or you do three tall planters together.

You could put a half-height white fence on the back and left side of the porch as we're looking at it, which would look like it had always been there, keep people from falling, and screen the rain barrel and compressor. Then a narrower bench or maybe a colorful chair. (extra points if it rocks a little when you sit in it.)

Or even a high shutter-style wall like this:

Vintage-Inspired Inglewood Cottage · More Info

But honestly, the proximity of your bench to the cliff would keep me from sitting there. A wall would help, as would a cushier seat.

SCREENED-IN PORCH · More Info

these are very reasonable and come in a multitude of sizes, colors and patterns.

Lattice Designs - Acurio Latticeworks · More Info

Just make sure it is tall enough to hide your rain barrel too.