Things more dense than the air fall and things less dense than the air rise. That's what I observe. That's the how things fall. I think we all get that one. The big question is why do things fall?
Saying that it is a curvature of spacetime causing things to fall (gravity) it is where I have the issue and would like to see proof. Why does the curvature of spacetime not effect the helium balloon? How were you able to witness and experiment with curvature in spacetime? Did you do an experiment where you were able to harness spacetime and prove this to yourself or did you believe what you were told?
As I've said before, I don't dislike your motivation, but I feel you are mixing the desire to find a flaw and what we currently hold true, and to learn for yourself. Have you taken any physics classes in the past? Its not a matter of listening to what you are told and applying formulas, its about learning the means of natural phenomena happening, and making sure it coincides with your understanding. After every single lecture, it all needs to make physical sense. And you build on material. Skipping from, what is gravity, to the neorelativistic model is jumping ahead 1000 steps, and a great way to cause misunderstandings. If you are still trying to rationalize whether these things make sense or not, start with the simple version before adding in additional detail. Gravity, Elves, Density, whatever you want to call it will always work the way we expect it to. We can represent it with equations, it doesn't matter whether the equation is solving for gravity, density, or elves. The point is that it exists and is observable. Humans have yet to find a situation where it doesn't apply the way we expect it to.
So far, I've only been using Newtonian physics, because its 99.99% accurate, without the 6 years of formal education you need to understand the most basic concepts of time. Fourth dimensional analysis is not fun and not observable. It requires you to restrict your bounds and use math operations to confine it back into 3 space.
Water "finding level" is an analysis of potential energy and fluid dynamics. "Level" is an arbitrary gravitational level point. After reading a lot of these posts, I think a major concern is people keeping their reference points consistent.