Yeah kinda. Pretty much everything, including numbers, that aren't vectors are imaginary.
If you want to apply the concept that "everything that changes is a vector," you can, by that same logic, give someone control over all numbers. Vectors are motion based alone.
No they aren't. There's a reason those are called "motion vectors" specifically. A vector is anything with a magnitude and a direction. Everything else is a scalar, ie something with only a magnitude. Scalars don't actually exist as anything but a concept. There's nothing actual that's a scalar, aside from volume and mass, as far as I know.
The only reason Osiris' control of scalars makes him second strongest instead of Ma'at's vectors making her second strongest is because Osiris can mess with people's powers by changing the numbers in them as they're actualizing them.
Everything actual is a vector. Even location is a vector.
I see why you say that, because in physics it's usually used in relation to movement, but it's not limited to it. For example, time itself is a vector, but time in relation to the motion of something is a scalar. If you're measuring the displacement of a ball from X to Y, then the time taken is a scalar. But if you're not measuring something against the time taken by that something, then time is a vector, because it has magnitude and direction.
For another example, while speed and temperature are scalars in concept, when talking about them within the universe, they are vectors. If speed is constant, it is still a vector in reality because reality itself is moving it. See also: Universe expansion. You can only view the constant speed of something as a scalar when removing it from reality, ie as a concept. Temperature is one of the rare exemptions to this if it remains at absolute zero. Since the temperature is itself a representation of the vectors of energy and smaller particles, if it is above absolute zero, ie no movement, then it is itself a a vector for the same reason that speed is. But at absolute zero, the vectors it represents are zero, even though reality itself is moving them. In that case, those particles/energy are changing their locational vectors, but their temperature is a scalar. However, keep in mind that temperature itself is a pure concept, just as most other scalars such as numbers, speed being constant, time as a single entity, etc. are.
Motion is the most common usage of vectors because motion is so prevalent in physics, but not all vectors require motion, really. Again, location is a good example. So long as something has both magnitude and direction, it is a vector.
To put it in the simplest terms: As long as something is an actuality and not just a concept, it will almost always be a vector. Volume and mass are pretty much the only exceptions I can think of.
I studied vectors; I know what they are. My point is that you're defining them too broadly.
Because we're not dealing with a specific instance. We're dealing with everything. Non-concept things. Almost everything actual has both magnitude and direction, so when the ability affects actual things, it affects almost everything. If we were dealing with the study of vectors, it would include a lot fewer things. But we're not.
Technically she would only be able to control vectors in three dimensions, considering time could be considered a vector.