Slaughterguard/Underdark Campaign Help {3.5}

[Machiavellian]

Since my old group is against the "End of the World" Campaign, I actually had to turn through campaign ideas.

Therefore, I decided to turn to classics: Slaughterguard and Underdark hybrid. I plan on using Drow as the main antagonists. Basically, I want the campaign to center around stopping a Drow Priestess from summoning an Avatar of Lolth to destroy the surface.

I'm planning on focusing my book scheme around the Underdark and Drow-Themed books (such as Plot and Poison, a Green Ronin 3rd party source book, and Drow of the Underdark) for monster setup, as well as adding the Scorrow from Secrets of Xen'Drik

Race-Wise, I want the players to use unique ideas, so I'm giving everyone a free 1LA (praying to God that the players won't abuse them) so the players are more unique critters.

Class-Wise, I want the players to feel free to test out new classes, so I want the group, and highly suggest/encourage oddities, variants, ect. I also plan on adding some KoK, Eberron, ect. classes that players could choose from. I'm also planning on designing a new Psionics system akin to the Spellcasting system so my players, who are all new to Psionics, can jump into it.

The players will start at lv1, since its a fresh and semi-new idea; it's new to my players...

4 things that I have to ask though:

1. What sorts of monster encounters should I do, since I like either mobs or complex encounters with one or two monsters and a environmental hazard.

2. Is the free 1LA too much to give my players, since they are normally used to a Core Only campaign?

3. Can somebody help me balance my new Psionics system??? I know what I want to do, but balancing it is a royal pain.

4. How do I encourage my players to play outside of their comfort zone?

[Machiavellian]

Anyone good at Underdark Campaigns?

[Machiavellian]

Anybody????????????????

[Chambers]

4. How do I encourage my players to play outside of their comfort zone?

4. Ask what the players want their characters to be able to do, and then find a way to do that with mechanics that they don't normally use. If there's a player that likes Fighters, explain to the player how the Warblade works. If there's a player that likes duplicitous sorcerers, show 'em the Beguiler. Paladin fanatic? Knight and/or Crusader.

Sounds like you know your players, so just find non-core classes that do what the players want to do.

[Machiavellian]

4. Ask what the players want their characters to be able to do, and then find a way to do that with mechanics that they don't normally use. If there's a player that likes Fighters, explain to the player how the Warblade works. If there's a player that likes duplicitous sorcerers, show 'em the Beguiler. Paladin fanatic? Knight and/or Crusader.

Sounds like you know your players, so just find non-core classes that do what the players want to do.

I have a player who uses Elf melee Ranger, a player who uses a Ratling Ninja or Drow Sorcerer, a female player who uses an Elf archery ranger, a player who is a Human Cleric, and a player who uses a Warforged Monk