That doesn't absolve them from understanding the lower level stuff.
Not actually infinite, and most of the combinations won't do anything at all.
Rather more think that they are good at it.
Doing stuff where you don't understand what you are doing is risky, and usually a waste of time.
Name one. People frequently come across circuits that don't do what they expect them to do, but most them work out what is actually going on before they risk trying to exploit them. What's required is a deeper understanding of what's actually going on - not always one that would satisfy a physicist, but still a better approximation to reality than you started off with.