Just so that you are aware, I do not think that "dumb" is the word that you were looking for. "Dumb" is an insulting word that means the same as "stupid." You may have meant "unclear." Just wanted to make sure that you didn't accidentally offend somebody.
Drip is much better. Sprinkers are quite inefficient as ZandraJoi pointed out. It's quite the waste of water, which aside from being bad for the environment can also be quite inefficient in cost.
Food waste is actually quite good for the soil. Composting is very good for the environment and is much better than filling up landfills with bags of trash.
Yes, you will just need to find the right plant. Does it get a good amount of sunlight? There are still some options if you do not get much sunlight there.
The most effective way is to pull weeds by hand. If you do not pull up the roots, they will just regrow. It is tedious and takes time, but it is the most effective way to do it.
Grass looks nice, but I feel that it is better to allow native plants to grow. It is better for the ecosystem. Lawns are killing native species and insects.