iGo First...
social: no thanks, i'll spend that time making scrolls if at all possible
class: uses prediction power to roll dice for clutch knowledge rolls or when he thinks he will be doing something important in a combat round (like tripping), if there is a major npc in combat (not a basic goblin) he will use it each round to see if he can get a good attack roll.
casting: mage armour as soon as it looks scary, grease for tripping or disarming, colour spray for aoe control. only 2 scrolls to start with paid for at full price as thats all he can afford. 0th, presdigitation is a must for any wizard, jolt for ranged touch attack if needed (target already injured npcs), message for whispering at range.
crafting: makes scrolls at 5% off due to hedge wizard, will knock up a few buff scrolls to start off with and expand as the game continues, will spend 4 hours a day while adventuring as noted in item creation making scrolls.
combat: cast mage armour, control situation, use jolt, trip with true strike if necessary to escape. always has a scroll in hand (probably silent image) for scrollblade/shield, good AC (17 with mage armour), good willpower save, weak fort save, safe to take a hit at 10 hp.
wave 1: provide words of encouragement and cast jolt a few times, no point wasting a spell on 3 goblins. move to provide flanking bonuses with scroll blade if required.
wave 2: if possible grease the direction they are coming from to slow them down/make them fall, advise party to draw back into somewhere the goblins can be funnelled to make most use of grease, continue jolting and providing flank bonus. enlarge the monk or the oracle from a scroll if they feel the need to hit harder (probably oracle as it allows them to reach with heals as well).
wave 3: colour spray dog/rider, jolt/flank, CDG dog/rider if no one else can.
uses a scroll of silent image if the party needs a break to make an image of a large dog (knowledge nature +9) which looks very real, appears to be charging the goblins and shouts to the oracle in celestial to make it bark.
teamwork factors: not a weak caster who will die in one hit, only slightly worse at tanking than the oracle or monk so can get mixed up and provide flank bonuses.
analysis: good ac so not a weak link in the party line up, can provide flanking bonuses as required if the oracle needs to step out of position to heal and can also provide cover for the oracle to cast without eating AoO's. colour spray is probably the best 1st level spell available when at first level and grease is a very strong multi use option. due to level restraints all wizards are not very useful at lower levels due to the resources available but even with low spell usage the diviner can still contribute to combat with jolt and scrollblade. over time i would think that this character will become a much more useful party member providing buffs and control as well as crafting items for the party but for the first few levels and for a combat role will need to pick his places to land his spells.
if the party wish to take lookout as their 3rd level feat (the oracle probably will since i'm controlling it as well) the diviners powers of foresight will benefit the party greatly just by him being present.