I think the class should have more of a focus on controlling and debuffing the enemy rather than buffing allies/self. It just doesn't seem to fit with how I picture a mesmerist, especially when a lot of their abilities specialise in enchanting others, yet none of their tricks really do. This way they could even make use of their medium BAB (with the right build/archetype) and do some solo, rogue-style adventures
I think being able to use tricks to give more assorted penalties to opponents would be nice. Confusion, flat-footed, forgetting the mesmerist etc.