IMO it is hard to overdecorate. I would agree with filling the tank more as long as you have a hood or something covering the tank...
This is my sorority tank, and as you can see you can really heavily decorate :p They love to have cover and tall plants to sleep on, so if anything, I would add at least one plant that will reach the surface of the water when the tank is fully filled. He will probably be happier with more resting places near the surface and more hiding places. They don't hide a whole lot and usually they like to come to the front of the tank when you approach it so I wouldn't worry about him hiding all the time. I do like your floating log!