Roses are beautiful. And they have a heavenly scent. And...
But first, don't use sprayed roses for any of these.
For food, it's mostly the rosehip (fruit) that gets used. The larger the rosehip the easier the picking and processing - so the best rose for rosehips is the rugosa rose (Rosa rugosa).
Rosehips are used in teas, jams, jellies, and similar; foods where the itchy hairs have been strained out or otherwise removed.
You can make a tea of roseleaf if you so wish. The taste is rather bland.
You can also make a tea of the petals of roses; your tea will taste of perfume. Or put a few petals on your cake, into the pitcher with ice water, into the punch bowl, or similar. The color is rather pretty, though.
Roses "lift the spirit". I use them for depression, insomnia, things like that, usually as a tincture, because the tea is just too much perfumy taste in one go.
The stronger the scent the stronger the action. Rosa damascena is very good, as is Rosa rugosa. There's probably other strong-scented roses, as well, but I've used those two.
The green parts are just Yet Another Rose Family Astringent.
The rosehip is considered medicinal because of the loads of vitamin C it contains.
There's the rose salve, of course.
And a vinegar of rose petals gives the bathroom tiles a nice shine and a very nice but rapidly fading scent.
I've also made rose deodorant powders.
You could make your own perfume with strong alcohol and rose petals, either dried (70 % alcohol) or fresh (95 % alcohol). Dab a drop here and there, too much alcohol dries out the skin.
Or you could distil your own essential oil (EO) of rose petals. You'll need some 100s of kgs to get a liter or three of EO, though; there's a reason EOs are as expensive as they are.
... itch powder. I'll say no more.
Have I forgotten anything?