Trying to determine the internal construction of a BLDC Motor
Q1: Does this mean it is constructed as if it were a PMSM with
sinusoidal BEMF rather than a BLDC Motor with trapezoidal BEMF?

It has probably been designed for low cogging rather than specifically for sinusoidal BEMF. I tested a dozen 14 pole outrunner motors designed for 6 step commutation (which favours trapezoid BEMF). Some have strong cogging, some are 'lumpy' with ill-defined positions, and some are weak. But all bar one produce close to sine wave BEMF even though that is not required for their intended application.

Rotating the shaft it cogs 24 times...
The least common denominator for 14 poles and 24 cogs is 1, an
impractical number of slots.
Q2: Is it possible to know the number of stator slots?

Probably not, though you might be able to narrow it down to a few possibilities. All my motors have 12 stator slots, and of those with well defined cogging all bar one has 12 cogging positions. However the odd one out has 36!
With distributed windings several adjacent stator slots can share a single phase, but cogging is determined solely by the alignment of magnets to stator arms (the windings play no part). In a 3 phase motor the number of individual windings should be a multiple of 3, so the stator slots should also be a multiple of 3. The number of magnet poles is a multiple of 2. 14 poles are commonly combined with 12 slots in outrunners, but an inrunner with distributed windings could have a higher multiple (eg. 24).
So the question is, does your motor have 24 cogging positions because it has 24 slots, or are the magnets aligning in 2 positions per slot? Without opening up the motor (or contacting the manufacturer) you probably can't tell, but for normal operation you shouldn't need to know.