Hopefully without spoiling anything, the game needs quite a bit of talking and investigative work, do not neglect those or you might spend a lot of time idling for the roleplay sections.
I really wanna say ranger, but that STR makes carrying weapons a struggle.
Druid might work better, meld your gear into your animal form, or load them onto your pet!
Dwarf is a strong choice for either, with buffs to prime stats. Also the whole 'armor doesn't slow you down'-thing considering your STR.
Chance Savior seems to be one of the better trait choices.
.... I like you kineticist idea. You really, really want to do that. Hell, be an Aquakineticist, and you don't even need armor anymore.
You're going to be encumbered regardless of what you're carrying, so play an Evangelist Cleric focused entirely on casting. Encumbrance isn't actually that harsh of a penalty unless you have class features that get locked out if you're encumbered, and spells are not one of those.
Wait.. how is STR 4 even possible given PFS rules?
I'd embrace the low strength and play a gnome or halfling sylvan sorcerer. Str 2! To avoid losing mobility you ride your animal companion.
Heck, fluff them as paraplegic and explain that your companion is necessary for you anywhere.
Idea: You're of one of the following races: Aasimar, Kitsune, Undine. Multi-class Spiritualist/Oracle.
You're a young kid who grew up on the streets, not knowing his/her parentage.
You've disguised yourself as a human for so long, you might even think you're Human (each of the races has an option for appearing more human, or being more easily disguised).
Oracle:
Mystery: Nature, Ancestor, Heavens, **LIFE**, Lore, Lunar, *Occult*, Outer Rifts, Time, *Wind*, Wood.
Curse: Wrecker Curse
Source PPC:BoF
The destructive power of the Abyss and its teeming hordes of demons seeps from your very pores and into your belongings and surroundings.
Effect
Held objects gain the broken condition when you use or equip them but regain their actual condition if employed by anyone else. If a held item is restored to unbroken condition, it becomes broken again the following round. Disable Device becomes a class skill for you and you can make Disable Device checks to destroy non-magical traps as a move action without the need to use tools or take any action beyond simply touching it.
At 5th level, whenever you attempt to damage an object with a melee attack, reduce its hardness by an amount equal to your oracle level before determining the damage you deal with that attack.
At 10th level, any attacks you make against objects and constructs automatically bypass any damage reduction they may possess except epic.
At 15th level, whenever you are dealt damage by an attack with a manufactured weapon, you can require the weapon’s wielder to make a Reflex save (DC 10 +1/2 your oracle level + your Charisma modifier) to avoid having the weapon collapse into dust immediately after striking you (magical weapons receive an additional saving throw against this effect).
Spiritualist (Ectoplasmastist/Fractured Mind Archetypes) (they stack):
Ectoplasmic Lash (Su)
At 1st level, as a full-round action an ectoplasmatist can manifest one or two lashes of ectoplasm tethered to her by wispy, ectoplasmic tendrils. If she manifests two lashes, she can wield them both as light melee weapons, each dealing 1d6 points of slashing damage (1d4 if the ectoplasmatist is Small) with a critical threat range and multiplier of 19–20/×2. If the ectoplasmatist manifests only one lash, she can manifest it either as a single one-handed melee weapon that deals 1d8 points of slashing damage (1d6 if the ectoplasmatist is Small) with a critical threat range and multiplier of 19–20/×2, or as a two-handed melee weapon that deals 2d6 points of bludgeoning damage (1d10 if the ectoplasmatist is Small) with a critical multiplier of ×2. Only the ectoplasmatist can wield or use these lashes. Dismissing any or all manifested lashes is a free action.
Emotional Spellcasting
A fractured mind's ability to cast spells is tied to the force of her own spirit rather than her connection to the spirit world. As a result, she uses her Charisma score rather than her Wisdom score to determine the highest spell level she can cast, the saving throw DCs of spells she casts, and her bonus spells per day.
This ability alters spellcasting.
You literally cannot carry anything, but you don't need to, as all the weapons and spellcasting you need is within you.
Break things with your ever-growing reach of ectoplasmatic tendrils.
Take Weapon Finesse, Weapon Focus (Tendrils), pump your Dex, and take Improved Sunder. Just smash things with your strange ungodly manifested tentacles?
Some neat ideas already, but I have little experience with psychics or kinetics, so I will try and give some different ideas...
These stats almost scream GUNSLINGER, (Pistolero, or Mysterious Stranger) great DEX, pistols are light and ranged, decent WIS for grit. And you have the con plus a d10 to sit and take hits if you really need to melee. Mix with any class that gives a familiar or animal companion and use them as a pack animal (that won't die day 1). A cestus with paralysis poison, finessed has a good chance to hit and get you some breathing room (Maybe), or at least threaten.
Summoner could also be really nice, Ant Haul cast daily so you can carry your gear, and an Eidelon to use up your STR feats and weapons, get alchemical focuses to make cantrips dangerous (acid flask + acid orb + great dex = light crossbow damage and hit), focus feats make this even better, and I think I saw a magic trait to add +1dmg to a single spell or element.
It looks like your party could use a melee/tank, Eidelon and summons might be handy. Or you could take weapon finesse and specialize as a DEX defence touch attacker, Unchained rogue 1 would give you finesse, plus 1d6 on sneak for non STR dependent damage.
A 4 STR is almost too low to fix with racials and bonuses, I would say embrace the Arcane, and avoid the martial, Haramaki, Crazy high DEX, range, and Mage armor are about your only options for defence.
And lastly, witch/oracle necromancer, who needs to be strong when you can have minions do it for you =p
We are playing the same campaign and it is useful to be able to fight haunts. There are plenty of them and they are quite persistent.
1) to prevent manifestation could be useful to be able to detect evil for free as a paladin or if variant multiclassing is allowed, take paladin as secondary class. Then you have a chance to spot them and not to enter haunt infested area.
2) you also need some ways to damage them. You can use wand of cure light wounds, cure spells, channel positive energy or lay on hands, but I prefer to cast disrupt undead for free. Only wizards, sorcerers, maguses and inquisitors can cast it. When you get to some area with magic shop which also has ioun stones, you could probably buy (1 000 gp) one which allows you to cast it with another cantrip/orisons casting class.
As for strenght=4 – playing small character saves means that lot of equipement weights only 1/2 normal value (for medium characters).
Child half-elf
Ranged bard would be fine
Oracle (bones, dark tapestry, life are all thematic)
Your cha and wis are strong oracle or shaman candidates