First grow critical +2.0 auto, during flower can I trim fan leaves? Also can I remove whole branches at the bottom that aren’t getting light/bud sites?
Yes you can.
I’ll add that buds don’t use light. Leaves do. The plant is capable of shuttling the nutrients the leaves manufacture throughout the plant where they are needed via the stem system.
Okay thanks guys I was worried with it being an auto flower if I cut off a low branch it might not have time to heal
Here is a little lower bud that was completely under the main canopy.
I try to leave as much as possible without blocking air movement. Its not huge, but its frosty enough for me. 
I had already harvested the upper canopy at the point this was taken.
Its just the genetic structure of the plant to grow smaller buds on the lower areas.
They do the same thing outside where they get plenty of direct sunlight that moves across they sky at different angles. .
Toes are not always needed, but sure look better in place, rather than gone.
Lower branches are not getting enough light, true.
Possible advantage for keeping, re-vegetation (exploring success for re-veging).
Taking 3/4 a branch, always leaving one node for potential growth in future may be advantageous.
IDK, but try multiple training and harvesting techniques. S-N is my guide for grow learning. Thanks @Spiney_norman.