Im still pretty new to growing. I know this subject is up for debate on weather two or not. I think some will say yes it's ok during veg in limited amounts, some will say no don't it will stunt growth and slow things down. And 99% will say no way during flower stage. I have seen great results on this site from people carefully tying those branches tucked out of the way. This would be a great way to get the light you need without slowing growth too much. But like I said I'm still new to this just going off all the reading I have done, not from personal experience.
Yep. I do it all the time. It's a technique called defoliation. You'll get higher yields. I always cut my fan leaves off, starting at week three. I look at 'em as rocket engines. Just as they dropped the engines when the rocket got out of the earth's atmosphere, I drop the fan leaves once the plant reaches the end of the 'stretch'. Yes, I'm high.
If you have removed fan leaves in Veg, then you can do it in flower also. If you didn't do it in veg, I wouldn't risk it(OK! I'm lying, I would try it ). YOLO!
EDIT: Might as well super-crop that top cola while you're at it.