Should the magnetic field outside a conductor be considered?
I'm wondering, will the induced current produces another external
magnetic field near the edge of the disc?

Yes it will and it's not an induced current it's an eddy current caused by an induced voltage in the conductive disc that circulates the eddy currents. Faraday is clear about this; voltage is induced and that's why we have faraday's law of induction related to voltages and not currents.

If yes, will that external magnetic field influences each other when
the current changes?

If you mean will it influence the alternating magnetic field that created the eddy currents then yes it will. Due to Lenz's law it will seek to reduce that originating field within the disc: -

But, the eddy current field will enhance the originating field outside the disc.

Should that field be concerned or can be negligible and why?

I don't understand that question; probably a bad choice of words but, taking a guess, it might be negligible but that's truly down to what a person decides is or isn't negligible.