There are no qualifications, limitations, or disclaimers on the commandment to love others.
"Inasmuch as ye have done it . . . " means, literally, if I call someone a mocking or demeaning name, I have called Jesus of Nazareth that same name. It means if I won't try to listen respectfully to someone, no matter what they are saying, I am refusing to listen respectfully to Jesus of Nazareth.
The commandment to "do good" to people includes those who curse, persecute, and spitefully use us. We are commanded to be "perfect" in this love - and, in the original, that means being "complete; whole; fully developed" in love. It means, in practical terms:
There are no qualifications, limitations, or disclaimers on this commandment.