Hello ! If your leaves are dark green then it coulb be a N excess like you said , so to get rid of it you can flush before you apply some flowering nutrients. I am not a defoliation pro but in your case your plant is so bushy that if some leaves are blocking the light to some bud sites then you should remove them to ncrease light penetration , but if you don't wanna get rid of them then you can also knit them together. I hope it will help you 😁👍