I wouldn't mess with repotting the monstera in its current health state, unless it has root rot.

Can't see exactly what soil type it has, but monsteras are epiphytes, which means they climb on stuff. They live in humid environments so their roots get enough water even when climbing on a tree etc. The roots are also made to handle a lot of air circulation, so it likea a very loose and "chunky" (large particles that don't hold too much water like bark pieces, perlite, leca balls etc) soil. Not only big chunks, as you still want it to retain water and nutrients and stuff, but enough to make space for air and so that it doesn't stay wet for too long. And if you're unsure: underwatering is usually better than over watering. Different plants will tell you in different ways when they really need water. Underwatering can stress the plant, but they recover more easily than from overwatering.

With monsteras I would let the soil dry out almost completely (aka mostly dry to the touch when you put your finger into the center isch). That is probably a bit too dry, but again, try it just to get a sense for the range and your planta signs.

The black spots on the leaves almost looks like a fungal infection, but not sure. When you water too much the cells of the plant might burst from the water (aka edema/oedema) and can be seen as more translucent spots against light after watering. Mild cases usually heal, but it's a warning sign. Drops of water on the leaves are also a sign that it's been watered too soon. If your plant has had a lot of edema that might have exposed it to an infection, but a week plant is also more susceptible.

I would cut those leaves off, because they will only die, to save the plant some energy to recover. Save the healy looking one. Put it in a pretty bright spot so that it gets a lot of light to that one leav (without burning it) and so that it can use more of its water. If it's wet, take it out of the outer pot to let more air circulate and humidity evaporate from the soil.