Mohammed, First, creationism is NOT a philosophy. It is a scientific theory. You say so yourself “It is the most excellent feature of creationism, that with it one can describe the facts of how the earth came to be,” See, Creationism is very much theory of how the universe came to be the way it is now. Prior to about 1800, YEC was the accepted scientific theory. From about 1790-1831 scientists (nearly all of whom were theists and many were ministers) found data (facts) that falsified young earth and a world-wide Flood. IOW, creationism could not explain the facts. In fact, the facts contradicted creationism. Many scientists (such as Lyell) then adopted the theory of “successive creations” in which God had successive large creation events (such as dinos) spread over hundreds of millions of years. However, that was being frayed in the 1840s and 1850s as scientists were beginning to see that species (Latin for "kinds’) were not stable or immutable. Then came Darwin, who discovered an unintelligent process – natural selection – to give design. Single interpositions of God in creating individual species gave way to God establishing “general laws” that gave rise to new species.
But your post typifies what Dr. Topp was talking about: despite all the evidence showing creationism is wrong and the history of Christians overwhelmingly rejecting creationism in the 1800s, here you are saying it “describe the facts”. For you, too, the perception seems to be that accepting evolution or science means accepting atheism. You think there is a “materialist philosophy” as an inherent part of science that denies the existence of God. You are fighting for your theism against atheism. But you are on the wrong battlefield and have the wrong enemy. Science isn’t your enemy. Evolution is not your enemy. Below I will explain somewhat how science works.
If you want to read more about the history of the theory of creationism, I suggest Davis A. Young’s excellent book The Biblical Flood, A Case Study of the Church’s Response to Extrabiblical Evidence
Second, “Creationism should replace materialism as the underlaying generic philosophy of science.”. There are 2 forms of “materialism”: methodological and philosophical. Philosophical materialism is basically atheism. However, despite the pious wishes of some atheistic scientists (Dawkins, PZ Myers, Atkins, Schaffersman, etc.) science is not philosophically materialistic.
Science is methdologically materialistic. It is a limitation of science and comes directly from how we do experiments. Let’s say you want to scientifically determine the causes of plant viability and growth. What do you do? Well you get a bunch of plants and then test whether things like water, soil, sunlight, and air are necessary. How do you do that? I think you already know: You put a plant in conditions where ONE of those (at a time) is missing. That is, you don’t water one plant. Another you put in a lightproof box. Another goes in a vacuum chamber and you pump out the air. Another you take out of the pot and hang so it’s roots dangle in air (no soil). When you are done, you will find that all 4 of those material causes are necessary for a plant to live and grow. So, is God necessary for plants to survive and grow? How would we test that? What plant can we point to and say with certainty “That plant has God in it” and what plant can we point to and say with certainty “God is not in that one.”? I don’t know of a way to do that, and neither does anyone else. If you can, then a Nobel Prize (at least) awaits you. I’m not being sarcastic.
What methodological materialism means is that science is agnostic. It is neither theistic nor atheistic. Your sentence "The conclusion God exists, is equally logically valid to the conclusion God does not exist. " is valid as far as science is concerned. Stephen Jay Gould expressed it very well:
“To say it for all my colleagues and for the umpteenth millionth time (from college bull sessions to learned treatises): science simply cannot (by its legitimate methods) adjudicate the issue of God’s possible superintendence of nature. We neither affirm nor deny it; we simply can’t comment on it as scientists.” SJ Gould, Impeaching a self-appointed judge. Scientific American, 267:79-80, July 1992.
So, when I’m speaking as a scientist, I’m agnostic. My faith that God exists comes from outside of science. Science will neither confirm nor deny it. IF, however, I make up a theory on how God created, then science can go to God’s Creation (the physical universe) and test the theory. Science cannot test the existence of God Itself, but it can test the method. For instance, atheists hate the various studies on intercessory prayer. Why? Because they show an effect of intercessory prayer. And hidden behind intercessory prayer is the hypothesis that it is God answering prayers.
Now, if you want to challenge atheistic scientists who mistakenly try to make science atheistic rather than agnostic, then you are on solid ground. In fact, I’ll help. But trying to have creationism as an “underlaying generic philosophy of science”? Nope. It’s a falsified theory.
Now let’s get to “objective” and “subjective”. What you are getting at is concepts of evidence. David Hume showed in the late 1700s that ALL evidence is personal experience: what we see, hear, taste, smell, touch, and feel emotionally. Our conclusion of “beautiful painting” is based upon our personal experience of sight and emotion. The conclusion in this paper – Lucas, P.A. Chemotactic response of osteoblast-like cells to TGF-beta. Bone, 10: 459-463, 1990. – is what I saw. Notice I’m the only author.
The term you want in place of “objective” is intersubjective. Intersubjective experience is personal experience that is the same for anyone under approximately the same circumstances. Personal experience can differ from person to person. You and I can look at the same painting and differ about whether it is “beautiful”. The example I use in class is the taste of Brussels sprouts. So far, no class has had all members with the same “taste” for Brussels sprouts.
Science has made the collective decision to admit only intersubjective evidence. That places a limitation on science. It also reinforces the agnosticism of science. Science cannot say whether Moses parted the Red Sea or what experience Saul had on the road to Damascus. Science cannot say that your personal experience of God is valid or invalid. Because it is personal (to you) and because not everyone has personal experience of God, it lies outside of science. Science cannot comment on its validity. Now, you may ask how my paper is part of science, since it is only me as author. The idea is that anyone can see what I saw (essentially) if they follow the Materials and Methods section of the paper. And I took pains to be sure the results were repeatable for me. That is, I ran the experiment 4 times and got identical results (within experimental error) each time before I submitted it for publication. So, it should be intersubjective. Saul’s experience cannot possibly be intersubjective. Nor can your personal experience of God. Nor can the essence of a lot of relationships among humans. In fact, some relationships are ruined (such as marriages) if other people can get the same experience with a spouse. 
Now, I agree that "scientists should be forced to acknowledge this limitation on science. " I’m not sure who you mean by science, since I am a scientist. You can find quite a few scientists acknowledging the limitation:
“It is important to recognize that not all “facts” are susceptible to scientific investigation, simply because some observations and experiences are entirely personal. I cannot prove that someone loves his or her child. The emotions that any individual claims to have are not susceptible to scientific documentation, because they cannot be independently verified by other observers. In other words, science seeks to explain only objective knowledge, knowledge that can be acquired independently by different investigators if they follow a prescribed course of observation or experiment. Many human experiences and concerns are not objective, and so do not fall within the realms of science.” Douglas Futuyma, Science on Trial, the Case for Evolution, 1995, p 167.
Notice this is a book by an eminent evolutionary biologist who is showing that creationism is false.
There is a philosophy called “scientism”. It’s rubbish. Basically, adherents of scientism think the only possible knowledge is scientific. But scientists know that we live the vast majority of our lives outside of science, where we routinely accept non-scientific “facts” and personal experience as reliable.