Lastly, another two things to consider:
1) Every chumra has a counter ‘kula’. Meaning – if you advocate only buying certain hashgachos, you might be causing a monetary loss to other hashgachas and their certified foods/stores. If you require that davening should take a longer amount of time in shul, some people who can’t handle it, will just come later or stop coming. If you are more machmir on various hilchos ishus/niddah, you are decreasing amount of onah.
2) You always have to question what is the impetus for wanting to be machmir? Is it truly lishmah or is it rooted in ba’al gaivah…?