Operational amplifier, pitfalls, theory VS practice?

Question

Electronics

Those who came here, I suspect they are familiar with the op-amp (operational amplifiers), the essence of the matter is that the logic of the op-amp is not so complicated, it is mathematically possible to synthesize the necessary analog sections of the circuit in order to achieve the desired functionality, to make a comparator, amplifier, analog- a mathematical unit, but this is from the side of theory, I simulated everything in Multisim 12.01 Everything works perfectly there ... but once again the theory, in practice everything does not work or works incorrectly. I think for others it will also be interesting what and how.
The list of questions is as follows:
1. What characteristics of the OS do you need to know, what are they, what are they responsible for, what is important to us and what can be neglected?
2. Op-amp power supply methods, Unipolar \ Bi-polar, according to what parameter of a particular op-amp should it be powered one way or another, methods and methods, pitfalls, what should not be done?
3. Ways to improve the stability and accuracy of the OS, if any?
4. Diverse mathematical elements based on the op amp that can be connected to each other creating cells with different mathematical functions and their subsequent analog execution (solution)? (I mean ready-made blocks/sections on the OS)
5. What OS would you recommend, why, which ones are cheaper and/or easier to get?
6. Practically proven circuits based on op amps for various functions.
7. Ways to protect the OS from harmful effects, noise, interference, power surges, protection of inputs and outputs.
8. Causes of inappropriate behavior of the OS and diagnostic methods to eliminate them.
This is what I consider it necessary to find out, so if you have answers, write, I will be very grateful.
Perhaps you can add anything else you want to know as follow-up questions.

Answer 1

The logic of the ideal op-amp is not complicated. But real devices are far from the ideal model.
You need to greatly increase your knowledge of theory. Then most of these questions will disappear.
Short answers to your questions will not help you.

Answer 2

dude, horovitz and hill to help you.