Were they all blowouts? Close games? If we are 0-4, we likely have much larger issues than just Geno playing bad. We have a much better team, and what should be an elite defense than the previous two on paper and while that TD/INT ration is bad, it is likely not the sole reason we have the record. With our defense Geno's 7 ints, unless they were all pick 6s likely did not lead to 7 touchdowns by the opposition, so the team would have to be really bad in other areas as well.
Factor in the fact we are running a new offense and a new defense, Bowles has stated himself he does not expect the offense we are installing to be competitive until week 2 or 3 of preseason. Sheldon is suspended, and the defense will not be 100% perfect either in the first four games.
Also realize that whatever issues we are having on offense have an additional week to be ironed out.
In your scenario with better weapons, a better offense that Gailey has said is specifically designed for him, and a better team overall, you have Geno performing even worse than he did his first two seasons. That is just super unlikely. He was bad last year but clearly was better. It is unrealistic to think that Geno would perform that bad.
But it is possible. However, even if that happened I think it would be incredibly unlikely that they would move away from Geno after only 4 games. If that was a real possibility they would not be giving him the support he is getting. That is not to say that all the media and some fans hear would be out of their minds badgering Bowles about sitting Geno, and Geno bashing would be at an all time high, but I just do not see even in this scenario them sitting him after 4 games. Gailey has stated it will not be a short leash, and regardless of Bowles lip service to competition in camp I think they see something in Geno and are committed to it.