Others have listed all the top Faction Traits already: Enchanters, Wanderlust, Master Scouts, Lucky. Quick and the Decalon are also decent choices.
Personally, I like Binding a lot and usually take: Binding, Scholars, Enchanters, Master Scouts. No Armor as a malus.
Since this is a forum, everybody can argue about the top race, but honestly, it's not really a contest. Mancers have +1 move and you can give any unit roadbuilding for free.
That being said, I have a weak spot for Wraith, and usually play with them.
My Sov is almost always a Mage, so I pick Summoner. Warlock isn't enough of a boost, as casting damage spells is too expensive mana-wise, especially in the early game.
The other traits of my Sov vary. Procipinee's Crown is very strong on a Summoner. I almost always pick Brilliant, since the Spell Mastery is very useful. I tend to pick the No Healing as a malus, as Wraiths can heal quite easily.
About the exp traits: Potential is only worth it if you are planning on leveling a lot with your Mage Sov. Knowledge is good for your Sovereign.
Brilliant, again, good for a Mage Sov, as the Spell Mastery helps. General as a profession is pretty good if you do not like the specific styles of play the other (top) choices require.
