In most of the RM2 games I have played in the GM has not allowed any profession from the RM2 Elemental Comp as they are too powerful or do not fit the game.
MDC
Funny you say that. Our RM world was Elementalism only and Elemental Companion Spell User Professions. All spell users had to come from EC. All other non-spell user professions from all Companions were allowed. The closest thing to an EC spell user without using EC would be Force Mage and they were pretty cool.
I would say that Archmage offered the best choices and could easily become very powerful. I've used NPC Archmages against my players and at times, they felt like that had just a little to much advantage over the PCs, but when it's 4 v 2, I had fewer qualms. The Archmage was like having a Hybrid user with all lists as base lists, slightly higher than Pure Spell user costs for lists, but better then Hybrid spell user costs. It was the best of all spell worlds with very few drawbacks.
One member of our group made a Magus and he outgrew the power level of the other players in the campaign and the GM asked him to make a new PC, so I can see the Magus being really good.
I've always wanted to make a Maleficant. To me, their spell lists and their abilities seemed to be the most debilitating to a target, even at lower levels.
For non-spell users, I like the Assassin (Poisons are AWESOME!
) and Burglar and I have always been partial to Cavalier, but I think Leader can overtake a Cavalier for "shining" in game play. Leadership at 1/2/2 is a great skill to use in a party and has so many applications.