1) for myself, most often, the more abstract the landscape image is the better, so I wouldn't stop at retouching until I achieved that result (assuming it was even possible).
2) for most of my own work I have absolutely no reverence to depict a scene as it was, only to interpret it as I feel, hopefully making a good image in the process.
Retouching for me is only another process in addition to the original composition, exposure and such towards a final print. Albeit I am typically lazy and strive to make images that require no darkroom skills. Doesn't happen very often, but I don't like to rely on post exposure skills to make a good print, while at the same time I don't avoid them when they are appropriate.