Yes! It’s a really awesome thing about this fandom—and Sherlock Holmes in general—that it is so inclusive of not only homosexual relationships, but other queer relationships.
Just like everything else, asexuality and co. are experienced differently by each person. It’s not only what genders you’re attracted to and whether your desire is sexual or not. It’s also what you want from them, what activities you want to do with them, what qualities and characteristics you’re attracted to (some people have a thing for blondes! Some people like tall. Some people drool over smarts, or kindness, or a great ass).
So if you want to get a good grasp on the differences and what those relationships could be like, getting lots of input from lots of different people is absolutely the way to go. ^_^ And if/when you write it yourself, you might choose to pattern it on a specific example you’ve encountered/experienced before, or you might take qualities you’ve seen in many different examples and build your own, or—if you feel comfortable cutting loose and trying—you might run with whatever your imagination comes up.
Stories aren’t really about creating a political doll you can hold up as an example of your cause (which is not to say you can’t, and some people do that quite effectively). They’re really about creating characters whose lives and experiences are true and real to them within their own story. Chances are, whatever you think of, somebody in the world has experienced. 7 billion people means almost everything’s been done at least once, somewhere.