1. It is wrong to say " ...输出电压由于经过了跨导放大器,其DC 工作点就不再由电阻分压的divider直接确定了..." Basically, 跨导放大器 has inf. impedance and therefore Vout/(RFB+RIN)=VFB/RIN still corrects.
2. If "DC 工作点就不再由电阻分压的divider直接确定了" is true, the only reason is your loop gain is too small to keep the DC of VOUT stable