I agree with others on here about flushing. Flushing is for toilets. If you'll spend some time on the Advanced page, most experienced growers agree that nutes left over in your soil won't have any affect on your final product. Proper harvest time, dry time, and cure, those are what will affect your MJ in the end. Some growers will nute all the way until they cut.
I think your plant is ready for chop, chop. You can wait, but degraded THC can affect your MJ negatively. Don't forget, your Trics change color during the drying process. Also, I have pretty much stopped using my high power scope to look at Tric color. Look at your overall plant, at the obvious signals that she is done; change in leaf color, buds are done swelling, water consumption has dropped, and 70-80% of pistils have changed to orange, receding into the buds.
Your buds also look pretty small, at least from what I see in the pictures you posted. Next round, work on better lights, as light deprivation leads to minimal bud development.