1: Why are some religious people "afraid" of science?
I think it depends a lot about who you ask, probably more than one would think. Some people have no issue being religious and believing in God, while still accepting science at large. So for instance most stories in the bible (just using that as an example), like the story about Adam and Eve is not a real story, but that it was most likely written due to some other reasons, and that this doesn't change their faith at all. On the other side you have people that believe that every single word or account in the bible is absolutely true.
If one is in the latter group or leaning that way, obviously science causes some issue, as it doesn't support the account that the bible is giving. Evolution and how the universe began and work, is simply not telling the same story. So if you are convinced that the bible is true, obviously anything that claim differently is potentially a "threat" as it would show that the bible is wrong, at least in these parts. People rarely like to have their beliefs questioned for one reason or another, especially not when it comes to religion and it does actually requires a lot of work personally to being able to deal with it.
However there is a difference, between me telling you, that I think you are wrong about Islam for whatever reason I might have for wanting to do that, compared to me for instance saying that I can scientifically prove to you that parts of the Quran is wrong. Which is most likely because everyone knows that science works, whether you are a fan of it or not or simply think that only some of it is correct. One have to live on another planet to not accept that we have computers, mobiles phones, planes, cars, medicine etc. and that these are the result of science one way or another.
So you can easily disregard my opinion, whereas its a whole lot harder to disregard science, when it can be demonstrated to work or be correct. Especially because religions have no counter argument to it. Science is a method or process about learning what is true and more importantly what is definitely not true. Religions have no explanatory power, no method for achieving truth, you either believe or you don't. So honestly I think its more in frustration that people are "afraid" of science, because I think they know that their religion doesn't have the ability to argue with science, if one can put it like that. So science becomes a threat and the best defense against it, is to deny it or point out where it did wrong etc.
The problem for religious people that do this or support it, is that science doesn't care, in fact it encourage people to point out where it went wrong, so we can get closer to figuring out what is more likely to be true. Again as I said above, the most important thing in science, in my opinion, is to figure out what is definitely not true.
2: Is there truly a way for science to disprove God or deities?
As above, it depends
If you are going for science providing 100% clear evidence that God does not exist, then it won't. But then again, science doesn't really work in absolutes, but rather to the best of our knowledge. So for instance evolution, is it 100% certain? No, but to the best of our knowledge it is true, but we can't know for sure, whether evolution magically appeared yesterday, because God thought it should be like that, and simply made it appear as if it took billion of years. That is the limitation of science, and why it disregard the supernatural, because in theory it can do anything.
But if one can accept this limitation, then science can probably get to the place, where it offers a better explanation for the beginning of everything than that of a God. But the process can and will be very long, because its obviously not easy. But where science at least makes process, religions makes no effort in explaining anything. God did it and you just accept that!! But for a lot people, we don't buy that, especially when again, science seem to suggest that it didn't happen like the scriptures say, and whenever you ask a religious person, how do they know, you get nothing, because they can't give any answer or even remotely come closer to fitting, what we observe with the idea of God as it is written in the stories.
So for me personally, since you know im an atheist. Science simply seem to offer a better explanation, or at least the possibility of getting closer to the truth than the religions can. I have nothing against God, but then again, I have nothing against unicorns either, but I don't believe they exist either.
To go back to the beginning, science doesn't disprove God, but when something becomes so unlikely to be true, is that then disproven? And for me, it is enough that I am willing to refer to myself as an atheist.
3: IF there is no "verifiable" proof of God, does that means God can not exist?
Believe I answered that just above
4: If science one day did discover Gods existence, does all religions fall away then? or does this part of science fall away?
Good question
I would probably think it would go the other way around. Science would most likely fall apart as we know it. Because pretty much the whole method would be unreliable, we couldn't count on anything being as old as they appeared, so what we might think took billion of years, again could have happened just 3 minutes ago. We would probably do things the same way, like making medicines etc. simply because how should we do it otherwise, but in general I think the whole scientific community would collapse. I think you would have a huge increase in whatever religion the God(s) belong to, so all current religions might collapse and we would all praise Odin
(This obviously assumes, that we as humans could tell the difference between something being highly technologically advanced and that of a God. So for the sake of argument let's say that it was in fact God(s) )
