Is it safe to harvest?

2-3 weeks flowering is a really short time. Idk of any strain including autos that will finish in 2-3 weeks. Patience is a virtue, if it's not something you had before growing you had better acquire it. As far as cutting of your fan leaves goes. It's a major debate in the growing community and from my experience it goes like this. Defoliation done correctly, starting from when the plant has about 5 nodes, can add a great amount of weight when keeping a plant short. If you start off young and start by removing 10-20% of the fans and continue this until a few weeks into flower your plants will stay short. The 1/2 gram bottom nugs will turn into 1/2 8th plus rocks. This method would be great for a 150 watt set up because light penetration would be better on a short plant. Your girls look tall and skinny so I'm guessing you defoliated later in their life. I wouldnt move your lights higher. A 150 watt light doesn't penetrate much so going higher will hinder bud formation. I personally would supplement with a mixed spectrum of cfl lights for side lighting. These can get extremely close to your bud sites, stay reletavely cool and add needed lumens. For future grows I would recommend a scrog for such a small light. The name of the game is light. Keep ALL of your buds at the same level and your efficiency per watt will be at full effect. There is a good 150watt club floating around the Internet, I would suggest reading the thread.