When ever i get a favorite the one who did never leaves a comment. I think that there should be an option on your page that says "check this to force people to comment in order for them to favorite". That would be nice, and I'd have a lot more comments.
I wouldn't favorite something if the page forced me to comment. I don't leave pointless comments, I'm not going to say 'I like it', because that is what the favorite is for. I don't always have some point I want to make, or something specific I want to point out, I just like the art because, and there's no point commenting to that nature.
If you want comments, browse dA and comment on peoples work. You'll get them in return.
There is a good saying that you shouldn't talk if you have nothing to say. I donīt see a reason why people should be forced to comment it they don't want to. BTW I don't understand what your problem is. Your most commented piece has 8 comments and your most faved just 3 favs. There are people who get a way more favs that you and don't complain about it.
Hell no. Sometimes, I don't want to say anything because it's a super popular artist, and everything has already been said, or it's just stock I'm favoriting for later, or, I'm speechless, which is a god damn compliment.