I don't know anything about Stripe, but I'm guessing that a good number of the type of people that would want to use your module will be small-business owners that would not want to modify the perl their OS ships with

I reckon that would be a very accurate assumption...

For that reason, for the Perl version I start with v5.006 (because that's what Module::Starter specifies for Makefile.PL and check to see if I am using any Perl features that were not in that version. If I am, I ask myself if my code benefits from the later features. So, I have process I am happy with for selecting the minimum Perl version.

Additionally, I have v5.16.3 running on my hosting so (almost) everything gets tested on that. I don't feel there is any need to support anything older but I will if it is only a case of changing a digit in Makefile.PL

Perl ships with a program corelist

Thanks for that - I didn't realise that. This will save me time looking up release versions in the online documentation :)