Actually, Silencher you could almost make this work towards your advantage....since this half demonic rogue/fighter character has the majority of the items let him initiate most of all the encounters and take the majority of the "hits" for the team....if he doesn't and just decides to play dumb then just don't help him in battle in any way. My advice is just remember you are the spellcaster and the person who can stand back from the battle. In a lot of cases spellcasters don't need magical items to become powerful so I would start to focus more on your ability to cast spells towards the group rather than making items.
Play the "selfish" wizard card if you have to. After all you are more than likely the most intelligent character in the group. So if you decide not to do something well thats just it. Negotiation within the group can never go astray...
