Its mostly safe if you compiled it from revanced.app or from github.com/revanced

As for account bans, I've been using it after vanced died and my accounts (including that has purchases) wasn't banned so maybe its a regional thing(?), I can't 100% tell.

PS: if you decided to give it a try and use your accounts, make sure to use the "vanced" version of microg, idk why but vanilla microg doesnt work with revanced in my experience