The way I understand it is if they are yellowing or dying you should pull or cut those. Reason being is that the plant will still try to push water and nutes to those leaves which in turn takes away from the rest of the plant that is still healthy. As far as the green ones that are shading the flower sights that would be a judgement call on you. I do know that the big fan leaves help the plant with photosinthisis. Hope this was helpful for you. Happy growing!!