I dont use multiple profiles myself on my phone but what you described is absolutely doable with graphene :-)
each profile in graphene can have different google accounts or no google services at all.
I am sure others will have better advice than me but I would set a phone up for your described scenario the following way:
3 profiles:
- owner profile
- 2nd profile
- kids profile
then I would either use the owner or 2nd profile as your detox one and the other as the full blown one.
as for pins/passwords/fingerprint: you can choose the lock method of each profile. a PIN, a password or just a finger print.
the "kids profile" you can just give it a pin as locking method and install games and if needed google services with a separate google account just for downloading games.
This is what I like about graphene. It gives you choices and options to use your phone how you want :-)