You are basically playing a charm-centred caster, so go for what works for that.
You need to get your Int up as far as you can to make the saves as tough as you can against your abilities. Don't skimp your defences, and don't forget to take a 'back up' power - energy ray is great, or crystal shard so that you can pack a punch if the mental stuff fails. Otherwise, mind thrust will deal deadly damage when it works.
Other useful powers at an early stage are mind link to help the whole party coordinate together, and don't forget those lovely mind-reading powers. Empathic transfer is very good if your party lacks a strong healer, especially the hostile version.