It's not something that might happen, in my eyes Minko needs a friend or someone that reaches out to her and that's what Ohana have been doing since the first episode and not something that she might do in the future. So I find it quite relevant but like I said Ohana probably would have done it regardless of Minko lashing out or not.
I don't think her good will means she doesn't deserve any animosity but that's not what you said either. But as for the reason being debatable, ruining her plants and getting her in trouble at work and slapped are pretty clear in my eyes. And her actions in the second episode add more fuel to the fire, it's barely been a day since Minko got slapped and a customer is complaining to her because of Ohana so it does directly concern her because she has to deal with the consequences.
So if we count out the fact that she tells Ohana to die (Which I do agree is bad), are the things she tells her justified?
But I do completely agree that she should take it up with Tohru.
She deserves credit for trying but as stated in the anime itself with "careless work does nothing but get in the way" or as other says the best of intention can lead to the worst outcomes. But she tries and that's a good thing but more importantly learns from her mistakes which people have pointed out to her. In the end I do agree that people shouldn't hurt others for their own selfish reason and it'd be great if we lived in such a world.
I can't remember anyone actually telling me to die so can't comment on it but I probably wouldn't punch the person, it'd be stupid of me to go to jail or pay fines to that person because of it. But mostly likely I wouldn't feel good and be angry if it happened.
Though I still think most people should rage against people like Tohru instead.