In my opinion, haggle is not of much use, Intimidation is of limited use as persuasion can be used in many of the same situations, Inspection is also not very useful, finally as far as I remember if you pick a clan that has Obfuscate stealth is not much use at all once you pump that up.
As for tips lockpicking, hacking, persuasion are greatly useful and take a combat ability of some sort. Though you can get through the main story taking none of them, except a combat skill, so don't feel obligated unless you demand to be able to complete as many side quests as possible. If that's the case, lockpicking and hacking are a must.
