about pdf/a... until recently there was not even an easy way to figure out if pdf is really pdf/a; now there is (verapdf) and it's crazy complex piece of software
and maybe I'm wrong but the only way to convert arbitrary pdf to pdf/a with open source software is to convert it to postscript and back with ghostscript - which is affero licensed... with all the possible problems it entails. (there is old version that is just gpl, works on most pdfs but is 15 years old or such.)
i needed to deal with pdf/a in a previous job... was not fun.
and maybe I'm wrong but the only way to convert arbitrary pdf to pdf/a with open source software is to convert it to postscript and back with ghostscript - which is affero licensed... with all the possible problems it entails. (there is old version that is just gpl, works on most pdfs but is 15 years old or such.)
i needed to deal with pdf/a in a previous job... was not fun.