A lot of that was you not reading my post. Here:
-Why doesn't the theory of gravity seem to apply to small particles~"-It does. Gravitational lensing is a common and easily visible effect of gravity on photons. To the best of my recollection, gravity is accounted for in some very precise models of particle interaction.
-~and electrons?-I'm not aware of any experiments which specifically demonstrate gravitational effects on electrons.
-Also, you're wrong about the forces. Electromagnetism has a positive and negative force associated with it, so do weak and strong nuclear forces (see the names: weak/strong, opposites. Like I said earlier)-All three or four fundamental interactions are attractive except electromagnetism.
My particle physics is beyond rusty, and it is actually the case that the electroweak interaction manifests as both electromagnetism and the weak nuclear force and it is attractive/repulsive depending on unlike/like charge and spin.
However, I stand by what I said:
-That's simply what we observe, and any "plot holes" are the responsibility of reality. Or God, if you're that way inclined.
I'm not certain what your third paragraph is asking for, if you want me to teach you modern physics from scratch "with graphs and numbers" when you already have a conclusion in mind, then you are out of luck. Fortunately, because this is reality, there are many places you can learn these things (even
whole buildings!), not just from a handful of forum posters. I've heard good things about
this place but I've not used it.
As for the question "why is the universe so finely tuned for life?", it's an old question, but the anthropic principle gives one answer: if it weren't, we wouldn't be here asking. Also,
would life be impossible if the physical constants were a little different, or would the universe and any life in it simply be
different? I've heard various answers, but while it's a (vaguely) interesting philosophical distraction it's not exactly an experiment we can run at this time and I'd refer you to my earlier point: all these things are simply what we observe, if you think they're weird, take it up with God.
/edit: a black hole "popping up" in our solar system wouldn't doom anyone if it was in a stable orbit. Or at least, it wouldn't doom them any more than something else with the same mass "popping up" would. They aren't all powerful devourers, just very steep gravity wells.