Priest version doesn't list hybrids so corrupting mundane creatures seems out.
Unfortunately Fire and Ice isn't really clear on whats meant by the word
elemental, as hybrids, constructs, and entities are all listed under the section entitled "Elementals". In my game (and the rest of this post) an Elemental with capital E is a traditional elemental (floating ball of fire) and lowercase e means any type of elemental (hybrid, Elemental, construct).
We ran into this problem as well for gating... Gating states you summon an elemental by type, but gives no further info. Since you are in fact gating an elemental from the elemental planes we decided that you could gate hybrids that live on the plane as well as Elementals. Elementalists are able to summon specific types of elementals (Type I, Type II) and which elemental is summoned is determined by a roll (found in the Elementalists spell list).. we used those numbers to decide which specific elemental is gated. (after using the Priests roll to determine what type)
ehem,
And with the healing/enhancement list i don?t see why i should not have a protecting familiar, if it?s our best fighter why not. i rather loose a familiar, then a comrad.
The mass restriction alone makes a combat familiar a tough proposition, not to mention the icky ramifications if the familiar dies. About the only 'combat' familiar I'd consider creating with the priest is a flying creature with a (infused) breath weapon. And for that to be at all effective the GM would have to be talked into allowing the familiar to gain skill (OB) with the breath weapon. But it's pretty obvious (especially if you read the Essence Comp.) that familiars were never meant to be fighters.
If your looking for a fighter...
I'm playing a level 6 Elemental Light Priest in my game and I have a mastered Light Elemental Servant. Its quite useful in combat. Especially if I cast a few buffing spells on it. It dosen't have a high OB but its difficult to hit, and one of it's attack options is 4 attacks a round giving it a 20% chance, each round, of rolling open ended, and any crit causes an additional elemental crit of the same type. Use it's high speed to get in behind an enemy while PC's are in front and it's actually quite effective.
Further depending on how deep the GM wants to go, Elementals gated in by priests can be scary mean because they corrupt whatever they touch (or touches them).. so hitting someone cases poisoning. An unfortunate weapon that hits a gated elemental has a chance of being corrupted (which could cause it to explode) In my game we kinda streamlined the whole thing, because rolling resistance rolls for every successful attack done by a hireling would take too long.
At Level 4 you won't be able to master a normal level 5 Elemental Servant, however there are rules in creature companion for randomly varying the level of creatures. So perhaps you can convince the GM to roll it and keep trying to gate in elementals until you get a lower level Elemental Servant. Or just gate before a combat and keep it 'controlled'.
Lastly for familiars we kinda glazed over the whole intelligence issue. There are many contradictions in rolemaster. The Farie Dragon, for example can bond and become someone's familiar all on it's own (the PC need not even be a spellcaster) however the Farie dragon is above animal intelligence. We felt that the intention was that a Priest could have an elemental as a familiar. Obviously the relationship would be different then a traditional familiar. A gated familiar is a spirit pulled from its own plane into our own, so it's knowledge would be nearly useless here, but it could potentially be a great source of help should the PC ever visit the plane of it's origin. Also, it's perceptions would be dramatically different then a familiar with 2 eyes, thats already dealt with, if you wanted to see through it, get a few ranks in the 'familar senses' skill, the same thing you'd have to do to see through the compound eye of a insect familiar or the 8 eyes of a spider familiar.
Zitos, if you really want a good familiar, I'd consider looking into getting 3 ranks in the "Animal Summons" list from the Summoner's Base Lists (Channeling Comp). Costing a total of 24 DP's this would give you access to the True Familiar spell. Again not too useful as a combat creature, this spell does create a much more generally useful familiar.