What you say is correct. I remember reading a Venerable's description and explanation of a monk's rebirth as a swarm of mosquitoes, apparently because of kamma from a previous life.
Again, what harm we cause is a matter of choice. Do we choose to drive on the highways at seventy miles per hour and scrape all manner of insects off our windshields, or do we choose to take the side roads at thirty and leave most insects unscathed?
Do we choose to buy so-called "organic" foods which are largely planted and harvested in less harmful means to the environment and put up with a few bug marks on our fruit and vegetables, or do we go for the prices afforded by corporate farming methods using insecticides, which destroy thousands upon thousands of insects?
As for eating honey: The bees did and do not volunteer giving their product (honey), which was produced by their labor for their offspring. Therefore, like milk, eggs, and cheese this violates the precept: "Take not what has not been freely given."
But, on the other hand, so vegans don't feel too special: Taking apples, berries, apricots, strawberries, grapefruit, oranges, cantelope, and etc. violates the exact same precept if you acknowledge the fact that plants are life-forms.
Which brings us back to: "Life needs to eat other life in order to live."
What Makes an Elder? :
A head of gray hairs doesn't mean one's an elder. Advanced in years, one's called an old fool.
But one in whom there is truth, restraint, rectitude, gentleness,self-control, he's called an elder, his impurities disgorged, enlightened.
-Dhammpada, 19, translated by Thanissaro Bhikkhu.