The best types of combat in a proper CRPG involve a system purpose built for computers, rather than trying to make a system designed for tabletop gaming work on computers. Real time is vastly superior to turn based. As such, the best CRPG combat systems are those used in Final Fantasy 12 and in Dragon Age. Both allow you to set up a set of conditions under which your party will operate during combat, allowing you to define what each character will do to a terrific extent. This not only minimises the need for pausing but also means that all those really easy fights are over fast, which is good, while still allowing you to take greater control when you need to for the really tough fights.
How could combat promote role playing is a lot harder question to answer. Short of allowing for the taking of prisoners (Options: imprison, release, execute) which so far as I'm aware no CRPG actually does, there's little that can be done once combat actually starts.
Options for avoiding combat (sneak past, bluff, intimidate, fight, disguise, etc) offer many chances for role playing, however.
As for the role of combat itself in an RPG, the best use is to either add flavour to the world, increasing immersion and believability, or - far more importantly - to advance the story and/or plot. Endless fighting for it's own sake has no place in a true RPG.
