Is it ok to dissolve wasabi in soy sauce ?

Technical speaking, no it's not ok. It's considered better to keep the soy sauce as clear as possible for better look. And also, there are some seafoods that go well with other condiments such as grated ginger and if you have wasabi dissolved in soy sauce, it will kill the flavor of the other condiments and it will all taste like wasabi. But there are some Japanese people who do dissolve wasabi and I think it's ok to do so if it taste better for you that way !