I answered about bulb in other thread.
As far as clutter, some stuff to interact with is good, just don't add so much that the chicks have no floor space - a practice roost, things to hop up on and jump off of, a shallow pan of dirt to roll around in, a clump of weeds to pick at. How many chicks are you picking up? 4x4' is a pretty generous space to work with as long as you don't overload it with babies.
As far as clutter, some stuff to interact with is good, just don't add so much that the chicks have no floor space - a practice roost, things to hop up on and jump off of, a shallow pan of dirt to roll around in, a clump of weeds to pick at. How many chicks are you picking up? 4x4' is a pretty generous space to work with as long as you don't overload it with babies.