Darla's got so used to my voice now because I'm constantly talking to him
It's quite useful to talk to them to let them know you're around, I find it makes Darla marginally less skittish
It entirely depends how quickly they settle in, but let him go at his own pace. Rushing a skittish Robo, I've found, does more harm than good.
It depends on the ham as to whether you'll see him in the daytime. Darla doesn't come out until late in the evening most days, but he's nearly always up in the morning, so I feed him and talk to him then. I dare say he comes out during the day too, for a drink etc, but I'm not usually near his cage during the day
It's so cute when he comes out half asleep, though -- his ears are flat and his eyes are barely open and he looks so sleepy
ETA: Meant to say, love the name!