“but Judaism is still Judaism and even if they reject parts of it, that doesn’t negate the fact that they’re still practicing in some way.”
“The only people who call themselves practicing Jews who really, truly aren’t, are Hebrew Christians (so-called “Messianic Jews”).”
These 2 statements of yours are contradictory. The so called messianics also practice in “some way”. According to you, whats the difference what the person rejects, so long as they practice in some way you should consider them pacticing judaism”.