Main suggestion: Make XP gain worthwhile OR increase drop rates with TRUST rather than reducing it. You're penalizing players by twice the amount by not only reducing item drops using TRUST but also telling them that leveling is very, very, very slow. I know they want to encourage people to use it as a last resort but if that's the case, increase the freakin XP gain.

EDIT: There's no good reason to level TRUST NPCs since there's no actual beneficial reward for doing so other than being able to use them in higher and higher dungeons which is not a reward in itself.