I mean he's taking time in that more often than not, he's been peripheral (it's not a criticism, it's understandable at his age, playing out of position too), he's not the only one though and he's amongst much older players. When he's played well he's shown all the potential and promise we know he possesses. It'll come soon enough, this season will stand him in good stead.
Yes, and he's still developing physically. There's that long period when form seems dependent on the effects of those changes. When he came here he had a great spell, then he grew a bit physically and faded in terms of performances, and got frustrated as a consequence, then he acquired more strength and poise and started to regain some confidence, although in truth he wasn't exactly performing so well as to demand being picked when he did get his chance in the first team. There's a long way to go for him, and I doubt if even he knows what his real range of strengths will be once he's finally settled physically. I quite like to see him being rested as often as he is. He's a rare talent and the coaching staff need to monitor him carefully as he progresses. Sterling looks like he can just push on throughout the season but the English league is in many ways a hazardous environment for a young flair midfielder like Suso. He could get worn down by the worst aspects of it before he's really blossomed as a mature performer.