Interesting and very meaty question, AhDistinctly!
I think death affected Keats's world view immensely. And I'm not only thinking about the deaths of his family members--but also of the death and illness he must have encountered at Guys during medical school. I'm sure that experience greatly influenced his ideas about the "poet physician" and all that that particular calling prescribed.
I don't think I'm alone when I say that Keats's premonition of his own impending death caused him to focus his poetical efforts with an almost lazer-like precision enabling him to accomplish more poetical feats of genius in his last creative year than most writers can accomplish in a lifetime of work. It's said that the low-burning fever of Keats's tuburcular infection actually aided his imagination--the irony of this fits perfectly in line with the many ironies of Keats's life and the "light and shade" of his work. So in a way, death helped create the poetry that still lives today
Brave Archer wrote:At the same time,I think that had they all live to see into there winter seasons,I believe that we would have gotten much better poetry from him.
I have to disagree with you, Brave Archer. I think, had Keats's mother and dad lived, he wouldn't have turned to poetry in the first place. He needed poetry to help him deal with the pain and suffering of being the eldest child in a broken family. I can't exactly remember the quote but someone once said that you if you are to be a poet, you must have some tragic experience in your life first. I don't know if that's true--but that seems to be the trend.
Again, if Keats's brother Tom had lived, I don't think Keats would have matured as quickly either intellectually or poetically. He certainly wouldn't have fallen in love with Fanny Brawne if he had his beloved brother to occupy his heart--I think he fell for Fanny because he was particularly alone when he met her and his heart was vulnerable. I think Tom's death was the tipping point in Keats's poetical life--Tom's death and the thoughts and feelings it stimulated in Keats influenced some Keats's greatest works including La Belle Dame and Ode to a Nightingale.
I think if Keats's life had been more comfortable or conventional, his poetical career never would have taken place.