I also simulated Spec's latest from post #27. Apart from some round-off error in his calculations, it satisfies the goal. I would however quibble with the fact that the problem statement gives you a reference of 1.00V, and he actually used a reference of -1.00V. If I was grading his effort, I would deduct some points...
I plot the deviation (error) from the desired output of the three respective circuits. The ideal would be a flat zero mV line. The green line (mike's) comes closest...
Mike, your simulation of circuit #27 is incorrect. For example, at the zero point the simulator shows an output error of 9mV when the nominal error can be very closely calculated to be +- 5uV * 20.482= +- 102.41 uV, +-5uV being the nominal input offset voltage for the OPA192. The worst case output offset of is +- 20uV * 20.482= 409.64uV. The opamp input current is +- 5pA so, in practical terms, that can be ignored. If a perfect opamp were assumed, there would be absolutely no offset error. How a simulator can say anything else throws doubt on the simulator or the implementation. And how you can't see this by a cursory inspection of the circuit is surprising.
It is not specified what the output impedance of the pressure transducer or voltage reference is, so how can you plot an error. Also, an error band giving +- deviations would be more meaningful.
The requirement says that the voltage reference is 1V. It says nothing about any orientation of the reference or the transducer for that matter. In the real world references can be a voltage cell or a shunt voltage reference (including Zener diode) which can be connected in any sense (not a serial reference though). This orientation of the voltage reference is not important to the exercise anyway, especially as changing the sense of any signal is trivial.
Your simulations are incomplete and difficult to read because the text is so small. I can't make head nor tail of the simulator circuit of post #9, and I have been designing similar circuits for years, so it would be a complete mystery to a newbee.
No opamp is specified, there seems to be two undefined outputs, and as far as I can tell that configuration will not work because it is a fundamental tenant of that architecture that the reference voltage must be higher than the transducer offset voltage. If you are fixing that by putting a potential divider across the transducer, as in Kerim's circuit, that contradicts your statement that your circuit of post #9 does not load the transducer. Also there is not a complete description of how the simulation was done- what assumptions etc.
You are inconsistent: On one hand you complained about me posting a circuit when you had already shown a circuit in post#9 and now you are analyzing the circuits to the Nth degree.
This is not about designing a functioning circuit, or demonstrating who is the best designer, it is about helping the OP understand how this type of circuit works and how to do the calculations. Besides which, you can make any of the circuits arbitrarily accurate, within reason by using an appropriate opamp, and by calculating the resistor values to the Nth decimal place. Even so an error of 9mV only corresponds to an accuracy of 9mv/20V= 0.045% of full scale range. Most, voltage references would not be that accurate and pressure transducers certainly are not.
The architecture of the circuit in post #13 is not only commonly used, but is a lot simpler to understand and design. As it is much easier to calculate the resistor values to change the offset and gain, because there is little interdependence, the circuit is also a lot easier to re-scale. There are other advantages too.
Please stick to technical matters, and also please show the basis of your claims with a circuit analysis and calculations and not simulations. Simulations are not the real world and the models are not verified as Texas Instruments and National Semiconductor point out. Also there is the old maxim: garbage in, garbage out.
spec