I will try to share my thoughts on this matter. I will say I like your comp. I believe mage is the best option. Macroing easy dps rotation shouldn't be hard. A mage with a Wand is very competitive depending on how much you want to manage them. A level 26 Mage spam casting Rank 5 Frostbolt is about 45 dps (better with stats but this is the baseline) A wand requiring level 26 does 26.4 dps. So depending on how much you want to manage a mage they can still do a baseline amount of damage. The Int buff for your party is way to good. Water and portals just a bonus. If all you use the mage for is CC one of the targets that will be much better then a shadowpriest or another druid. I believe you agree that buffs that help others in the party go a long way. If you plan to farm strath or Scholo A priest might be best but I am still unsure how hard certain comps will have in that dungeon.

I believe the gnome will cause you issues. I would look at how you want to start your team and go the easiest route to the first dungeons. Cutting the gnomes does cut the fear break but I would only change races if you have trouble running the shorter camera angle. Minmaxing races in my book isnt a big deal, especially if you do not plan to raid on the gnome.

Your team looks great hope it works well for you.