I give veggie's and fruit once in awhile, but certainly not on a regular basis. Whether you do or not is entirely up to you... there is no right or wrong way to do it. I don't add them on a regular basis, because I don't think they are necessary, but my dogs like them. I make up my own carrot, apple, broccoli, and celery mash for them.
As for supplements, I only give specific supplements that my dogs need. For example, I give my oldest gal a glucosamine supplement (Recovery SA). I do give all my dogs fish oil. I used to only give it to my boy as he has severe skin issues, but I've started giving it to all of them.
My babies: Sassy - Maltese X (9), Furby - Shihtzu X (7), Brynn - Boxer (3), Diesel - Boxer (1)
"Many of the Earth's habitats, animals, plants, insects, and even micro-organisms that we know as rare may not be known at all by future generations. We have the capability, and the responsibility. We must act before it is too late." - Dalai Lama