To answer your original question, as others have already stated, to what level one manipulates, removes, changes anything, is up to them. My main focus is on proper exposure above all else. I do the vast majority of my cropping when I compose the picture, not in PP editing. I do remove imperfections if they jump out at me. It's not always nature that puts them there. Many a time while photographing in a Arboretum or greenhouse, leaves and petals are stained with liquid fertilizer. I remove them. Some times, ok many times, I can't control the lighting well enough to prevent harse shadows, so I just kind of rework them. Leaves overlap flowers, I move them.
As for your picture, I dont' mind the vines from the weeds. It's nature. It's natural, and it fits the scene for me. So I'd leave them. Besides, as Overread said, it's a lot of work to do it correctly.