ADS8689: Calculate ADC(ADS8689)+ Amp(ina823) error

Hi， team！

I want to calculate ADC823+ Amp8689 error.

offset voltage error:

INA823:        G=1, V(OS_RTI)=V_OSI+V_OSO∕G=(20+140∕1)uV=160.06uV  V(OS_INA)=G*V(OS_RTI)=160.06uV

ADS8689:     V(OS_ADC)=Eo=±0.2mV

                     V_OST=√((V(OS_INA))^2+(V(OS_ADC))^2 )≈256.16uV

Gain Error:

E_G=√((E(INA_G))^2+(E(ADC_G)^2+(E_R1)^2 )       R1 is sample resistor(50ohm,0.1% )

       = √(0.01^2*2+0.1^2)

       ≈0.101%

Noise:

INA823:     En_ina=√((e(nr ) )^2+(e(ni ) )^2+(e_nv ) )^2 )≈153.48uV(Resistor Noise/Current Noise/Voltage Noise)

ADS8689:  V(FSR_rms)=0.5∙FSR∙0.707≈7239.68mV

                  E(n_adc)=V(FSR_rms)/(10^(SNR/20)) =7239.68mV/(10^(91.5dB/20)) ≈192.63uV

                   E(n_total)=√((E(n_ina))^2+(E_(n_adc))^2 )≈246.30uV

I want to know if there is something wrong in the above formula?

And I want to calculate total error(Etotal) ,including offset error, gain error and noise error.

Can I calculate like this?

E_total=√((V_OST/Vin )^2+E_G^2+(E(n_total)/Vin )^2 )=???

Is this formula right? And Vin is -10V~+10V, so I choose 2.5Vref as shown in figure.

E_total=√((V_OST/Vin )^2+E_G^2+(E(n_total)/Vin )^2 )=√((256.16uV/10V)^2+0.101%^2+(246.30uV/10)^2)=???%

I think there is something wrong and it's too small. Could you tell me which formula is wrong?

Thank you so much!