Well actually. Nearly all the academic subjects are based on aplying the scientific method. There's only a very few subjects that are exempt. The study of aesthetics being the prime example. Language is very much a scientific subject. It doesn't need more than a glance at linguistic theories to understand that. It's pretty far from unsubstantiated opinions or vague feelings.
You got me. All very good points. But as you say. These are all what if sceniaros without evidence. I'm not denying any of it. I think chances are pretty good that if we encounter an intelligence out there in space somewhere, we probably wouldn't register it as intelligence, or understand it's comunication if they tried it. It could go either way. The aliens could have allready come here and colonized earth, but without our understanding or knowledge, and they could just as well have judged human comunication as just random noise. We will never be sure.
As soon as anybody floats a theory like this I always compare it's merits to the flying spagheti monster theory. If the evidence is as unsubstatiated as it is for that one, then we might as well ignore it.
But most supernatural theories ignore the premises of how the brain works. It's just a chemical computer. There's no magic involved and there's no soul. If it is, it dies when we die. There's nothing that leaves the body when we die. This has all been searched for and measured to eterntity. I understand the philosophical premise where the external and internal are the same. But then you're in a quagmire of definitions. What is you? Is your actions the result of your decisions? If you somehow have power over your body, then we can define the external as being that which is not part of your chemical make-up in the brain. Now we're in a position where we can measure external influence. If there's no border between the internal and external then there's no you, right? If you do a line of coke, it's your brain that gets high, not the person next to you, right?
Now I think you're underestimating yourself. Intelligence or academic prowess isn't equated to skills in maths or sciences. I'd say that the most successful academics are the most critical minds. The ones that are the last to accept any theory. The ones who would never make do with, "sounds about right". That needs a sharp mind.