Actually Washington isn't a bad route choice at all, they're not up against Norwegian. Just Wow which isn't non-stop and BA/UA who tend to charge a lot.
To serve India and China they would need bigger aircraft, and I assume a British registration. Not inconceivable. Unless traffic rights are an issue, I think India has great potential.
There are a couple of places in Africa that would be achieveable in an A321. Accra for example is one I'm surprised no one has looked at.