I'm seeing some stuff in my house that I'm wondering is a sign of regular settling or a warning of potential foundation issues.

For context, the house is a long boxy 2-story modern house with a split-level style entrance with stairs going to the second floor, and a small set of stairs going down to the main living area.

Photo of both sets of stairs: https://imgur.com/p6nn9oF

Here's a view of the upstairs: https://imgur.com/6wOIh95

If we think of the house as being split down the middle lengthwise by the railing separating both sets of stairs, i think I might be seeing signs that each half of the house is settling in different directions:

• I'm seeing gaps between the stairs leading to the main living area which widen in the direction of the railing, the stairs also squeak when stepped on now too: https://imgur.com/95iMTg7
• I'm seeing gaps between the side of each stair and the wall on both sets of stairs: https://imgur.com/u7tTP8x
• I'm seeing a bulge where the metal pillar for the stairs leading to the second floor connects to the second floor, almost as if whatever the pillar is anchored to is slowly being pulled out:
  https://imgur.com/kP3yz2j
  https://imgur.com/3Gl22aC
• There's also a railing on the second floor which prevents someone from falling over onto the stairs - this railing has some wood trim and there's a gap forming between the trim and the floor: https://imgur.com/2zXXCmI
• I'm seeing some uneven gaps between the baseboards and the floor on the second floor - for example, in one of the bathrooms which bisects the house, there's a pretty big gap between the bottom of the doorframe and the floor on one side but not the other side:
  Gap: https://imgur.com/QMx4Hx8
  No gap: https://imgur.com/aW2vfep
• Some more baseboard gaps on the second floor:
  https://imgur.com/C2qXT6L
  https://imgur.com/i016AiM

Some other stuff:

• Seeing a strange wall edge in a bathroom on the first floor: https://imgur.com/6kj2sZm
• Also seeing a bulge in the wall by some windows: https://imgur.com/n5JRsQh

Should I be worried about this stuff or is this standard house settling? If this is potentially bad, what sort of professional should I have come out...a structural engineer? A foundation person? Thanks!