Yeah tho I'm not writing some wish-fulfillment otaku erotic novel like many do here, So I wouldn't consider them "lolis" they are just children, and I treat them like so.
No there shouldn't ahaha and if there is, anyone who uses it should be reported to the corresponding legal forces
I don't think there is an age, Loli it's more of a physical description of your character, if you describe it as a having a child-like body it's a loli, tho I think it needs to have sexual connotations?
Maybe? Haven't really ever read anything with that tag, but wouldn't it be better to look at the content first? If there is no sexualization or fucked up content shouldn't it be okay? Like I saw someone who used it to signal that there is a little girl in their story, never thought of that, on...