I shouldn't HAVE to define the limits outright, though; most of the time, I leave the initial balancing to the RPer, who I should hope has a general idea of the amount of power a character should have access to in relation to every other character within. If I deem it substantially stronger in comparison to the baseline of the RP, then I'll intervene and request a change... Like I'm doing now.
I'll leave it to YOU to determine the strength that should be okay for this scenario, mainly because I don't like being overbearing as a GM. As of right now, though? The limits are so loosely defined that they become VERY powerful, even if that may not be the case. So, uh... Yeah. Define better and tone it down better.

And, to be honest? Running checks by me over and over again gets repetitive, and I shouldn't have to do that. If there are guidelines in place that you set yourself, I should expect you to follow them... For the most part.