As others have said, a lot of the things you mentioned - hairline
cracks in the corners, popping sounds - are just things that some
houses do. The house we built in 1985 did all that stuff, but it's
fine.

The "floor tilting" that you feel when walking, could be a lot of
things, the subfloor is warped or delaminated, or some other problem.
Foundation settling is not the only possible cause. For that matter,
the tilting is not necessarily a serious problem. My current house is
old and has various tilts and uneven places in the floors, but they
don't mean it's falling down.

Have you looked at the foundation itself? Are there cracks in it?

If there are nasty looking cracks in the foundation, or if your peace
of mind is at stake, certainly consider getting a home inspector to
examine the particular things that worry you. It's hard to say without
seeing it, of course, but my sense from your original post is that you
may be worrying about it a little too much.