Sorry to cut through your artful philosophical language. But want to see if I can grasp your key concept here. Stuff exists, because stuff doesn't come from nowhere, stuff came from "God." Where did "God" come from or is "God" simply the property of the existence of the universe? Your getting pretty close to the tautology and reduction of the nature of "God" that by "God" you are only asserting the creation and continued existence of the universe.
No apology necessary. It's good to understand things directly and not let unfamiliar language obfuscate the ideas. You missed a few key points in the argument, so let me try to restate it in the same language you used:
1.There are reason for why things happen and why stuff exists.
If stuff didn't exist we wouldn't be around to question its existence or not. The only universe in which we can ask questions is a universe that exists, I don't see the necessity for a God to make such things exist.
2. If there were not reasons, then science and philosophy wouldn't work. But they do work.
Science requires consistency. We ascribe laws or reasons to that consistency based on our understanding of the processes at the time. Its why our understanding of orbits (gravity) has changed from ancient times to Newton to Einstein. Based on the current open questions in physics its likely to change again, either soon or maybe in another 400 years. But consistency is the key here not reasons. Consistency can be a property of reality that doesn't require a creator, which the more loaded term reasons implies intent.
3. As a matter of logic, either the reasons for stuff is found:
a. in some other stuff
b. in the thing itself, that is to say, the thing is self-explaining.
4. Stuff exists. That requires explanation, because stuff isn't self-explaining.
5. The existence of all of the stuff we see can be explained by external causes (as in 3a) but, of course, then those other things all also require explanation.
Best scientific argument for stuff is the big bang. Somehow there was a lot of matter/anti-matter/energy that was and somehow the matter/anti-matter wasn't quite in symmetry. Matter was greater than anti-matter by about 1 part per billion. Hence a matter universe. Do we know the reason for the big bang, not really. Are we the event horizon of a 4d black hole, maybe. Are we part of some infinite multiverse, possibly. Are we one of many universe bubbles that pops into existence and ours just happened to have the right properties to exist for quite a while. Big bang/God. I see no argument for intelligence there either way something just existed/happened and we're living in the after effects.
6. Either there's an infinite chain of causes for existence like that, or it terminates in something that has the property imagined in 3b.
7. An infinite chain of contingent causes doesn't make any sense; I can't copy a textbook infinitely without there being an original textbook that provides the text to be copied.
8. Therefore, there must be at least one thing which is self-explaining, and which provides existence to all of the other stuff we see (either directly or through a chain of things).
Still at its root you come back to stuff exists. Why is there a universe instead of complete nothingness and no time or space or God or anything? We'll probably never be able to fully answer that. Saying I don't know why things exist or that things are consistent (post big bang) doesn't mean that there was some intelligent all powerful entity ("God") that somehow had the power and energy to instantly create the entire universe.
If I were to concede (for the sake of a different argument) of such an entity. We can also debate the "goodness" of your God. I see no reason why we think such an entity would care about biological life more than they would care about the supermassive blackhole at the center of galaxies. Most (roughly 2/3rds) of the milky way is hostile to biological life. Too many supernovas nearby, not enough heavy elements, too close to the center of the galaxy. The universe as a whole, counting the space between galaxies is extraordinarily hostile to biological life. At the very best such an entity ("God") thinks of biological life as an afterthought or curiosity to their grand structure of creation. Looking out at the universe and the scarcity of intelligent life, no SETI signals, no signs of multi star civilizations. Biological life absolutely isn't the purpose of creation. Maybe a complete afterthought if anything.