why not get another angel? They're social fish and if you had another to keep this one company you would see more of him/her. This one is probably lonely - that's why he hides. That probably makes me sound like a fruitcake, but seriously, I have 11 planted tanks, 480 gallons and breed angels when the mood strikes me. Get another.
As for plants- the anubias and sprite and hygro all look great, hwy not give them some time to fill in? Let the hygro grow big before you trim it into multiple stems. The closer it gets to the light at the top the faster it will grow and the more shoots you will have. Try to be patient with them and it will work out great in the end. I know that's not what you want to hear when you are thinking redecorate, but try.
How about some swords? Vals should grow in your tank with your lighting and so would crypts. All three should get root tabs now and again since your substrate in inert. You may so want to try some API leaf zone or Kent freshwater plant liquids to provide some additional potassium and micros for the plants. That will help.
If you want to add more hardscape remember the most natural looking tanks will have matching rocks and matching driftwood. Don't do multiple rock types/colors textures in the same tank no matter how mice each individual rock is, it wont look good meshed together.