First, congratulations on your commitment to making the world a better place. It's not always popular (or safe) to take a stand on principle when the rest of the world is unaware or insensitive to matters you find extremely important.
However (you knew that was coming), many of your arguments and statements about global ecology have been clouded by a misunderstanding perpetuated by biotech and global corporate agricultural interests. Briefly, let's look at the two big Red Herrings. Afterwards, I am going to suggest a path forward that will bring strength and resilience to the plant-based movement.
Grassland ecology is quite simple.
1. Grass puts green leaves upward and roots downward during the growing season. The leaves use air, water and sunlight to make sugars. The carbon and water are stored in the roots as carbohydrates: carbon + water. If the plant is a food crop, we can often eat the leaves, stem and roots and derive lots of nourishment from them. If the plants are mainly cellulose, our stomachs have no way to digest them.