Let me try to answer this, it has been a while leaving the cement industry.

1- what is the Cement Mill Feed rate ?

Fresh feed is 152 tph

Total feed is 152+260=423tph

*provided the weigher is correct

2- what is the Cement Mill Output ?
152 tph (ideally, but I always look on bucket amps trend)

3- how much the Separator Efficiency?
No answer, need to plot a tromp curve to see the sep bypass,acuity limit, imperfection. In addition specific air load need to calculate through field measurement to determine its efficiency

4- how much the Cement Temperature at the Cement Mill Output and how can we reduce it ?
113 oC, the temperature is slightly higher than standard (110 oC). Increase mill ventilation theough suction fan. The screenshoots shoes that bag filter dp is low and fan speed at 48%, still having a room.

My Additional notes with limited info:
The sep reject is increased over the time showing the grinding is less efficient, in a long run it will reduce the cement mill output ( through bucket amps).
If this always happen, look into c1 and c2 end of chamber sample finess,1st chamber slots ( plugging?? Material might bypass through center screen) during PM. If no, add 1-2 drums media in 1st chamber during running time for a quick solution and observed before PM. Also can try reduce sep speed incase of blaine/residue is within specs ( possible change of clinker hardness/size at that period)