Maybe I should have said "All are acceptable, to me."
@hirashin You might want to be aware that, while I have been doing language stuff for ages, I'm pretty lax when it comes to things/usages as in your examples.
Also, I'm a descriptive rather than a prescriptive person, and I also prefer oral to written. So someone other than me might quote some rules, or at least elements of style, that are counter to what I might say.
What that means is that I have heard your (b) sentences any number of times (to indicate 'too often' or frequency), and I take that as a validation of the usage. I think it's okay, and I understand and all, but...
...if I were tutoring a student, or reviewing the manuscript of a speech/presentation that they were submitting, I'd probably suggest changing (in the (b) sentences) "too much" to "too often."