With regard to your first question, you're probably better off asking in the Tech Support Forum.
Not sure on your second question, but someone else here might know.
For the third one, you're best off leaving the older addons as they are (I'm assuming you mean things like Botania that are inherent parts of Regrowth.)
Yeah, I keep seeing addon out of date and an offer to get the newest version. Thanks for the technical forum link.
I'm trying to setup some permissions through Mcmyadmin and it says to use GroupManager so I'm wondering if anyone has any experience there ?