"xD i hate elves!!" rp has got to be the least interesting dwarf rp cliche you could possibly pick from. You'd be better off doing diggy diggy hole rp.
Not only is it not weird, I think its super cool to rp a gender you don't identify with irl. Being able to put yourself in the shoes of someone you're not and roleplay is a real skill, and in my opinion its the key to making roleplay really fun!