Hey there Nino. Sounds like he is a pretty good dog. I live by myself too and work 8 to 5. I crate my pits while I’m at work. I am able to go home on my lunch hour and let them out for a little. That is good you are putting him on better food. My female Kira eats grass sometimes without throwing up too. Most of the time its close to dinner time or ever since she was a puppy she would get mad and just grab mouthfuls of grass and pull it up (dork). He may always eat grass but it could get better with better food. A HUGE key when introducing to another dog is stay calm dont be jumpy or anxious. Also NEVER meet on a TIGHT lead. Trying to hold them back teaches them it could be unsafe or a bad thing. It is our first instinct to make them listen and not pull but I have tried this and it works much better than making them calm and pulling on thier leash. Also best thing is learn your dog. Get comfortable with him first to where you can look at him and know exactly what he is thinking and going to do. You might want to take him to a controled environment like obedience classes. Even if he knows commands it socializes him and teaches him YOU are the boss. Just take it day to day and be patient with him you see to be doing fine. One last note with the meet and greet don’t freak out on him if you meet another dog and it goes badly. It could be a vibe from the other dog. Always be aware of your surroundings.