Here are some thoughts you might find useful.
* Only the two main characters can interact with the NPCs, so do not waste charisma skills on your companions (Pet-Pal for instance)
* One of your main characters should have high social skills, while the other do not need them as long as you always interact with NPCs using your social skilled character.
* It helps a lot if one of your party member has a high perception, which is needed to detect secrets, traps etc.
* The three most important abilities are your main ability (Strength for melee, Dexterity for rogues/rangers, Intelligence for casters), Speed and Constitution. Everybody needs Speed and Constitution. Be a little careful of boosting two primary abilities (for instance Strength and Intelligence) since that might make your characters a bit weak if you sacrifice Speed and Constitution.
* Your social characters should have Pet-Pal since it helps a lot in many quests.
* Crafting is nice to have. Jahan can be a good craftsman (both blacksmith and crafting) since he has the trait that increases them by 1.
* One of your main characters should have Ledership.
* One of your party members should have Lore since it is nice to identify unidentified items and get some more information about your enemies when you examine them.
* Summoned units are very useful in this game since the enemies get another target to attack. One that is expendable.
* Lock-Picking and Pickpocketing are not necessary since there are normally always other approaches, but can sometimes be quite useful.
Your party seems to have a good combination of everything. Picking Jahan and Madora seems to be the best fit for your main characters. The only downside is that both your main characters are dependent on two primary abilities (Dexterity and Intelligence). Maybe it would be wise to focus on Dexterity for one of them and Intelligence on the other one?