I agree with Corion: you should now attempt to send an email to the module author. Now that you have vented here, remove the emotion, and just present the facts. For example, you could debunk the author's claim that the functions are "fast" by providing some reasonable benchmarks against your alternate code.

If the author does not respond to you in a reasonable amount of time (a week, a month?), start filing bug reports on the CPAN module page for the things that are actual bugs. Include snippets of code to prove the code does not behave as specified in certain circumstances.

If more time elapses, you can rate the module to share your concerns with other potential users.

I've noticed that there are no test results for the module. I wonder if it because the module is so new that results are not yet available, or if it simply because there are no tests. In general, if there are no tests results, does that mean there are no tests? In other words, do CPAN testers add some default tests for all modules?

Just piling on... the "Changes" file lists the version as 0.01, but everywhere else, the version is 0.85. That's probably a typo.

Update: I looked at the "MANIFEST" link, and there is a single, trivial test (I mistakenly took the OP's "there are no tests" to mean there are zero tests provided in the distribution's "t" directory). So, maybe it'll take another day or so for CPAN test results to appear.