1)What is the difference between sour and non-sour API 5L grades?
2)Especially considering different process parameters at the hot rolling process (soaking temp., finishing temp., coiling temp.)?
If you are refering to API 5L pipe in sour gas or crude service then most people write specifications which are more restrictive than or in addition to API 5L. For example, controlled chemistry, CE, Charpy values, hardness, etc.
For valves and other components specify NACE trim. (MR-???)