The point is: that houserule gives Druids the Sun Domain & Turn Undead and thus DMM...
It depends on the druid though. Some of the variants of druid cause you to lose your animal companion, such as the PHBII Shapeshift ability, or the Druidic Avenger. If you would lose your companion, you lose the domain too. You'd just have to think it through so that wouldn't happen. But, yes, I do see your point.
No, it doesn't. It's a houserule that straight out gives a domain for free. Hence, my amazement.
Ah. Well technically it's not allowed because it's a houserule and it's probably assumed that houserules can't be taken unless specifically said by the "it's allowed." I'm allowing it, but only on the premise of the Pathfinder game which has you switch out the animal companion for the domain, as stated above in an earlier post. Otherwise, it wouldn't be allowed at all because of the fact that it's a houserule in the book. It's not official, which means that the committee would deny it. Bring up how Pathfinder allows it under condition met, and they might back down.
@ archangel.arcanis - I'd say that you'd likely get away with the 2nd one more than anything else. These aren't my rules, unfortunately. If they allowed one FR book, they'd be entitled to allowing them all, and considering it took this long to allow any book to be used outside of core, I'm not pushing my luck. Especially since this game's already been shot down twice because I had it too open for book allowances (including the magazines), and not using 4th Ed.