Logically we should use Pariden?
Profession : Summoner or Warlock
i guessing Warlock is more powerful since summons are weak?
Warlock has longterm advantages, but Summoner gives you the Summon Shadow Warg spell from your first turn. Given how poor Pariden leaders are at melee, and how many heroes you acquire aren't especially good at this either, it's very, very helpful in the early game.
i read some people think since Pardien can later buy tomes that automatically grant apprentice abilities for all the elements, one should waste points here.
Still, it takes some time to research those , so i put in Fire 2 + Earth 2. For stone skin and flame blade - I hope to make my Sovereign a killer unit early on with those 2 spells. But with stoneskin toned down to 6+3 per shard maybe not so good anymore.
Again, the choice is yours. I prefer giving my sovereign L1, and with just a little time out for Exploration and the starting civics in Administration, going directly to Sorcery. Then you can buy elemental spellbooks. That way, it's possible to grab several good traits at once, such as Attunement, Natural Leader (lowers cost of heroes, so you can spend that money on spellbooks) Brilliant, and Scholar. Throw in Clumsy, and you can get a Crown, too, which is invaluable since you'll want to spell up one champion with everything you can find.
I pick vulnerable to magic -20% to spell resistance, not too bad cos my other traits will cancel them out at higher levels.
Except you're not going to let that sovereign go anywhere near melee, so why not use Clumsy, instead? Then you don't have to worry as much about the enemy spelling your monarch with Slow when he/she may be the only one with Haste to counter it.
World size : large
opponents : four
I want plenty of place to expand
magic strength : dense
I go for moderate magic strength, as this makes the less magical races more viable. Again, up to you.
More shards for me to grab using Arcane Monlith
resource frequency : dense
Also, moderate (my choice). If you're going to do this, consider setting neutral monsters to dense, just to give yourself more of a challenge.
Even more clueless about warfare tree. What's good to supplement my strategy?
Get Drill. Adds one to your allowed army size. Other than that, I'd save those for much latter. After you get Sorcery, you want to push for buildings that give you more population growth and above all, research (plus Merchant), and you want to go up the Magical tree on the hero branch to get the more experienced ones as soon as possible. You should be able to pick up enough gear by killing monsters and finding caches, without having to buy much.
A few other thoughts. Your first hero doesn't need to be a bruiser type to go down the Path of the Assassin or Path of the Warrior. I typically choose the latter for my first acquired hero, and only choose magical disciplines (such as spellbook advancements) when the other options are relatively unimportant to the build I want. I save my pioneers for cities, and use arcane monoliths to grab every shard I can find. If one is positioned near monsters I can't deal with at the time, I try to place the monolith as far away from them as possible. As my people acquire new spell advancements, I always check for further spells to cast on my melee leader (who has my crown, so no mana cost other than the initial outlay), and good ones to raise research, production, and food for my cities. Side benefit of monoliths: you can always shop, there. More spellbooks. Mounts. More places to trade in items you don't need.
Best of luck. Hope that helps. 
