I'm going to take a shot at this and will edit this post after thinking of a way to fit all that in
Building a WF paladin with a primary focus on charisma is a lot like ice skating uphill. Nevertheless, here we go:
Level 20 Warforged Paladin
Str: 14 - 6 build points (1 level up point goes here)
Dex: 10 - 2 build points
Con: 16 - 6 build points
Int: 14 - 6 build points
Wis: 8 - 2 build points
Cha: 14 - 10 build points ( 4 level up points go here)
Feats = Power attack, skill focus intimidate, 2 handed fighting, Toughness, Adamantium Body, Combat Expertise, Imp 2 handed fighting
Skills: (from points only)
Intimidate: 23
Balance: 11
UMD: 11
Jump: 11
Basically put one point into each of the above skills every level. Only intimidate will be a class skill so the others will go up by half.
Enhancements
Level 1:
Warforged Healer's Friend I
Warforged Damage reduction I
Level 2:
Paladin Toughness I
Paladin Intimidate I (assuming this will exist)
Paladin Charisma I
Level 3:
Paladin Extra Lay on Hands I
Paladin Bulwark of Good I
Warforged Constitution I
Level 4:
Paladin Extra Turning I
Paladin Extra Smite Evil I
Paladin Resistance of Good I
Paladin courage of Good I
Level 5:
Paladin Toughness II
Paladin Focus of Good I
Paladin Armour Class Boost I
Level 6:
Defender of Siberys I
Level 7:
Paladin Divine Might I
Warforged Toughness I
Warforged Toughness II
Level 8:
Follower of the Lord of Blades
Paladin Extra Lay on Hands 2
Level 9
Paladin Extra Smite II
Paladin Exalted Smite I
(save one point here)
Level 10
Paladin Divine Might II
Paladin Bulwark of Good II
Level 11
Paladin Resistanceof Good II
Paladin Extra Smite Evil II
Paladin Exalted Smite I - the saved point from earlier
Level 12
Defender of Siberys II
Extra Turning II
Level 13
Extra Lay on Hands III
save 1 point here
Level 14:
Paladin Bulwark of Good III
save 1 more point here (meaning 2 spare now)
Level 15:
Paladin Resistance of Good III
Save 1 point
Level 16:
Paladin Divine Might III - spends spare points and you will qualify for it with the level up into charisma (bringing your base charisma to the required 18 at this point)
Paladin Charisma II
Level 17:
Bladesworn Transformation
Level 18:
Defender of Siberys III
2 points to spend however you like (More Sp, save up for more toughness, more into exalted smiting)
Level 19:
4 points here to spend how you like (Could do Improved Damage Reduction II for all of them)
Level 20:
Paladin weapons of Good
2 points here to spend as you like
Final stats without equipment or tomes:
Str 15
Dex 10
Con 17
Int 14
Wis 8
Cha 20
Final HP without equipment or tomes:
20 - Base
200 - Levels
60 - Constitution
22 - Toughness
40 - Toughness enhancements
= 342 hp without any gear (pretty good)
Final AC with very basic equipment:
10 Base
13 +5 Docent
4 Paladin
9 Tower Shield
4 (Self cast shield of faith)
= 40AC (not nearly enough, but you can easily enhance this)
Final Intimidate without equipment: 32 (Equipment makes all the difference here, your intimidate will be fine for most of the game, by the time you get to something like Hound of Xoriat you will have enough equipment (and buffs from allies) to make your intimidate workable.
Such as:
23 from ranks
3 from skill focus
8 from charisma (assuming +6 cha item - this should be a priority)
15 from Intimidate Item
4 from Greater Heroism
1 from paladin enhancement (easily raised to 2)
So you end up with a fairly easily achievable: 54 - this isn't quite as much as it really needs to be for top level content in the game, but extra gear and buffs can push it even higher, and it's about as good as can be sensibly achieved on your build.
Final thoughts:
This build is compromised by virtue of you wanting an intimitank pure paladin on a warforged. However it will be a very tough cookie, particularly when in the Defender of Siberys Defensive stance. Damage will most come from Divine Might so be sure to use those turns wisely. Your turning ability will be decent, but to be honest turning things in this game is still largely pointless beyond level 10. Defender of Siberys generates mob aggro by hate (damage caused) rather than by skills, but it still matches up nicely to a tank build.
The build is far from optimal but it manages what you wanted it to do. Ultimately this is the character you wanted to play and of course it could be optimised by altering the parameters. For example look at what happens when I do the same thing on a Drow:
Str 14
Dex 16
Con 12
Int 14
Wis 8
Cha 17
On a drow I get less Hp but a massive amount more charisma, more dex to add to armour class and take advantage of the prestige bonuses (or even go TWF) and by applying the level up points different I can either end up with 16 Str and 20 Charisma, or 18 Str and 18 charisma. But then you'd be playing a drow and just another drow paladin