Because they couldn't occupy at all, and they know it especially with sticking to the plan from OTL (4 phases)
I dont understand.
They did have bombers capable of reaching everything when bases in Kuban (He111, Ju88) and did IOTL bomb some of the oil targets inside their reach doing major damage (Grozny/Tiblisi), so could put it out of commission if they tried by September before defenses were organized.
Because IOTL they were able to to great effect against the targets they chose and Baku wasn't defended from aerial attack effectively until some time in September. By then the damage would be done.
You missed the point. Yes they did the damage, but "why settle for bombing when you know that this can be defended against and worked around eventually?" Damage can be repaired. Germany has learned that from bombing britain...
Given the damage inflicted and the assumption IOTL by the German command that the Soviets had suffered a mortal blow and the move against Stalingrad/Maykop would be the knockout blow (the further rush south was out of desperate need of oil rather than a knock out attempt), at the time that seemed like all that was needed to win. As we know with hindsight Stalingrad and Maykop already were badly overstretching German forces and anything beyond that, impossible due to time tables of the OTL pre-split plan, was logistical beyond their capabilities.
So do the germans now think bombing stalingrad and the caucasus will win the war in the east? I dont understand. If they are more cautious, then there needs be a reason. If there is a reason, then the assumption that one needs to be more cautious cannot logically follow to the conclusion that settling to bombing will bring victory. Maybe my english is not good enough to present it, but it seems like a contradiction to me.