TPS62813-Q1: Question about switch frequency range and accuracy

Hi TI engineers

I'm calculating the worst case of TPS62813 and I need switch frequency range in my design.

There is a 1% 10K resistor connects FSET pin to GND . But worst case of resistor is 3% for 1% resistor.

Equation is 

Fsw(10K) range is 18/(10*1.03)MHz=1.748MHz   to  18/(10*0.97)MHz=1.856MHz.

PWM Switching Frequency Tolerance spec in datasheet is as below, -19%~18%.

My question is 

1) Need I multiple this tolerance to Fsw(10K) ?  In other word, what is the Fmax and Fmin for a 10K resistor(3% wcca).

2) Fs min is 1.8MHz,  so if the calcutation result is less than 1.8MHz,  what's the Fs min value.

Thanks!