Flushing is a personal choice. I don't use a ton of potions, tinctures, and high priced nutrients and have been growing for more than a few years. I think the idea for flushing arose when people started to use very high levels of nutrients and different compounds, as opposed to allowing the plant to grow with a much lower level of additions. I personally don't flush and have never had a problem with harshness or odd tastes... so I wouldn't get stressed out too much about it if you didn't do it.
The extra leaf that is left on the bud is also a matter of preference. The added leaf material WILL make it a little harsher, but not too badly, especially if it is cured well/properly, which is where most of the harshness and flavors are removed or added.
On a side note, why did your plant quit growing? Was it finished flowering or was there another problem with it?