Don't take these too literally.
Homophones and other liberties are taken.
My prefix is
My prefix is found at a funeral
My infix at any salon
My suffix is found at a table
My whole is just three letters long
My infix is
My prefix is half of a hundred
My infix is twice found in three
My suffix is one third of one
My whole is a sanctuary
My suffix is
My prefix is short for my whole
My infix will make your life better (perhaps)
My suffix is short for a corner
My whole is four letters (perhaps)
My whole is a British sensation
To the best of my knowledge, all findings are logical and each blockquote has an obviously correct answer independent of the puzzle as a whole, and can theoretically be solved as such. However, they are intentionally a bit vague so that the solver may need to use the overall puzzle as a guide.
This should help rule out things like 'BIL' for 1 (super obscure, if even a word at all, and makes no sense in context of this blockquote), or 'IDOL' for 3 (IDOL is 4 letters, not 4 perhaps).
Similarly, something 'at a table' might be 'fork' or 'element', but not something obscure or unlikely like 'sweater' or 'dance'.
If you already assumed this, here is a real hint: No elements are involved.
Solve this line 'make your life better (perhaps)' and the rest of the puzzle should quickly fall. "Do (dough)" is an excellent candidate, but there is something else, famous for this quality, which doesn't even require a homophone. But don't let that get your guard down; a homophone is needed shortly after.
Extended hint regarding one of the lines:
All around, on the media, in the news, I hear about how great it is; that I should look forward to and embrace it. I admit there are innumerable benefits, yet for some reason I am wary. Whenever it is mentioned, I find myself not thinking of the benefits, but oddly drawn to a quote by C.S. Lewis: "As man conquers nature, the mysteries of the un-known are stripped away for our own gain and power. They day may come when science rationalizes the soul itself; and the soul loses its power, and all that makes us human is lost; there will be nothing left to gain but our own destruction."