Skills problems
I looked over the skills for these pre-gens, and there are quite a few problems. First off, Nature is a Wis-based skill, not an Int-based one.
Halfling Paladin
The mod for an 8 Int is -1, not -2 (although you seem to have applied the correct -1 to all skills except Religion). Also, you haven't applied plate mail's -2 penalty to Str, Dex, and Con skill checks. Additionally, you haven't applied the Halfling racial skill modifiers or the magic item bonuses to Endurance from both the Cloak of Survivial and the Dwarven Plate.
Athletics (str) +4 [+4 (half level) +2 (attribute bonus) -2 (plate)]
Nature (wis) +6 [+4 (half level) +2 (attribute bonus)]
Religion (int) X +8 [+4 (half level) +5 (trained) -1 (attribute bonus)]
Stealth (dex) +4 [+4 (half level) +2 (attribute bonus) -2 (plate)]
Human Cleric
Nature (wis) X +6 [+4 (half level) +2 (attribute bonus)]
Dwarf Fighter
Endurance (con) X +16 [+4 (half level) +5 (attribute bonus) +5 (trained) +2 (racial bonus) -2 (plate mail) +2 (item bonus: Dwarven Plate)]
Thievery (dex) X +4 [+4 (half level) +2 (attribute bonus) -2 (plate mail)]
Half-elf Warlock
Diplomacy (cha) X +18 [+4 (half level) +5 (trained) +5 (attribute bonus) +2 (racial bonus) +2 (item bonus: Circlet of Authority)]
Insight (wis) X +11 [+4 (half level) +5 (trained) +2 (racial bonus)]
Nature (wis) X +4 [+4 (half level)]
Thievery (dex) X +4 [+4 (half level)]
Eladrin Wizard
Arcana (int) X +16 [+4 (half level) +5 (trained) +5 (attribute bonus) +2 (racial bonus)]
Endurance (con) X +6 [+4 (half level) +2 (attribute bonus)]
History (int) X +16 [+4 (half level) +5 (trained) +5 (attribute bonus) +2 (racial bonus)]
Nature (wis) X +10 [+4 (half level) +5 (trained) +1 (attribute bonus)]
Perception (wis) X +10 [+4 (half level) +5 (trained) +1 (attribute bonus)]