Sarfaraz vs. Rizwan is a useless comparison. Anyone with a functional brain would understand that Rizwan is the superior batsman, based on technique, performances, domestic averages, and also general game awareness. He has taken quite a few blinders as a wicket keeper, and there is no doubt that he is our finest wicket-keeper batsman.
Sarfaraz on the other hand had his opportunity with the side, and for so many years, he was someone who had the ability to be a reliable batsman in the top 4, but for some reason, he didn't foster that ability into anything tangible. This is mostly because Sarfaraz, who could have been a reliable opening option, hid himself at the back-end of the batting lineup, sometimes even sending the bowlers ahead of him. His stats as a wicket-keeper batsman are okay, at best he's going to average in the high 30s and won't be consistent.
I'll say this once, Rizwan in test cricket is far, far, far superior than Sarfaraz. He is genuinely a capable batsman, who bats with intelligence and grit, and in a short test career, he has already shown much more technical ability and resilience than Sarfaraz. Anyone who thinks otherwise needs to start thinking with a factual sense rather than being guided by their own opinions.
As a non-biased opinion, both are equals in ODI cricket with the chances they've been provided. Both are averaging in the low 30s, and haven't contributed much to the team in ODI cricket. Given that Rizwan's test form was quite mediocre before he made a comeback, I think it's fair to say that Rizwan should be given at least another series before we look for other options, because it could take some time for him to convert his form into ODI cricket.
In T20 cricket, a comparison is quite arbitrary and senseless, one bats at the top and was the leading run-scorer in the PSL whereas the other bats in the middle order and performed decently. Rizwan is again the choice for T20s.
But what exactly are the limitations of Rizwan? In his short career since the comeback, he has shown great batting temperament in test cricket, and is a genuine fighter for the team. In white-ball cricket, I think he's lacking the middle gear. In T20s, he can go full blast and try to bash whatever he can to the boundary, but in ODI cricket, he's not finding it easy to negotiate the excessive dot deliveries that he's playing. I think this is because of his play-style, he either needs enough time to get set, or he needs very little time to start hammering the opposition around.
Playing Rizwan in the middle order is a mistake in my opinion, because it's quite clear that he's being pressured into a role he doesn't know how to do properly. He can negotiate the new ball, and has a good technique to bat up top, so I think he should bat in that position as opposed to the middle order. 
The bigger question becomes whether or not we can remove one of Imam and Fakhar, and I unfortunately don't know how to answer that given the performances of both in the SAF series.
As for the influential body, this is basically what holds Pakistan Cricket down. People who believe in players being "lucky charms" and other nonsense need to get their heads set straight. Perhaps the only thing Sarfaraz did of note was tell the bowlers where to bowl, and it's difficult to know how much this helps, so I can't make a judgement on it yet. As a player, he's being supportive to the bowlers and as a spectator, that is appreciated, but as far as replacing Rizwan goes, I think we need to consider a few more options before returning to Sarfaraz. I think now is a good time to introduce Rohail Nazir, perhaps a touch of youth can end this debate. 
I'd personally give Rizwan 5-6 more ODI games to see what he can do in the middle order. 
If he can't perform, I'd replace him with Rohail Nazir first. 
A slightly different way of thinking could be to give Imam-ul-Haq the gloves, and train him to be a keeper. If not, then I don't really see many options left to try. I wouldn't go down the road of bringing Azam Khan into the team. 
Maybe Umar Akmal as keeper (sarcasm)?