This class seems way better with the changes. Even still, I don't think mental potency does anything. It scales up at just the right speed to make sure your spells with HD caps never quite work against opponents of an appropriate CR.
Tricks are really the big draw of the class for me, but even with the changes (which, don't get me wrong, are a huge improvement) it seems like the mesmerist will never have enough of them, or be able to have enough of them active simultaneously, given how situational and short-lasting the effects are. I like the effects, but knowing when to implant which trick in advance and in whom to most effectively implant it sounds nearly impossible since the effects are so situational. And most of the tricks have such short-lasting effects, implanting them in combat will rarely be able to compete with spells for reasonable usages of standard actions.
As written, these effects would be perfect if the mesmerist had at least twice as many daily usages (or better, they were just at will) and could have one active on each ally simultaneously right from level one. The effects would still be minor, but they'd have much better odds of ever being useful. Right now the mesmerist doesn't have the coverage or quantity to set up enough reasonable contingencies.