I've been told Hoodoo isn't a closed practice. Maybe a matter of personal opinion?

Norse, Egyptian and Greek/Hellenic are "free" practices, meaning no, they're not closed, anyone can practice them. Due to a recent effort to restore Greek practice which I know VERY little about so take all I say with a grain of salt, it seems as though people are starting to think that you cannot worship Greek god/desses if you aren't... in Greece? Part of the culture there? I'm unsure why, after all this time, it would be taboo for me to practice, but it may be that some think people are too disrespectful towards the Greek gods and that faith, as some treat them as equals or friends. It would be good to do research, of course, but that doesn't erase the fact that anyone can worship Greek god/desses.

Now for Celtic and Irish, I'm part Irish and would have no issue with someone else respectfully practicing. I can't imagine most others who are Celtic or traditional Irish would either. Perhaps that would be up to opinions, but I've known Celtic people who don't particularly care one way or another. It seems to be a rather open practice. The general rule is just be respectful. Love and light, friend!