You know how they say, "ask 4 horsepeople, you'll get 5 opinions?" This seems true of rabbit people, too!
There seem to be at least two factions, those who believe a rabbit should eat rabbit pellets, and those who are dead set against it! I have raised rabbits for more than 20 years (hence my screen name). I have always used an alfalfa-based pellet, and have had rabbits that lived to be 10 or even 12 years old. I don't know what it is about alfalfa that is supposed to be so bad, my rabbits seem fine to me!
I say, read what you can, learn what you can, and do what seems to make the most sense to you. After all, it's your rabbit and your life - nobody gets a pet to drive themselves nuts, right?
Your guy looks like a Mini Lop, 5 - 7 lbs is the right size for that breed. If he has two Legs, that means that he has twice won in a class of at least 5 rabbits, owned by at least 3 people. A rabbit that is registered and has 3 such wins is eligible for a grand championship. One of the wins has to be as an adult; perhaps he got his two wins as a junior, but didn't finish up well.
Pineapple and Papaya contain enzymes that help to break up furballs. You can buy the fruits dried but they should be fed in very limited amounts because they also contain a lot of sugar. You can also get the enzymes themselves in pill form at a lot of natural foods stores, some rabbits love 'em!