Your first question is the most important. 12 awg solid copper wire.
Don't use a fuse, use a breaker. on my list is to upgrade my breaker and maybe this thread will help me get to it but the standard circuit breaker is adequate.
outlets don't matter as much as people think they do but a quality outlet should be used. Most use Hospital grade. The main thing a good connection as cheap ones loosen up.
I put in 5 outlets and a 240 outlet. I have half the outlets on the red leg and half on the black leg. If I need to plug something in like a noisy switching power supply for a Roku, i plug it into the opposite circuit that my amp is on.
But people exaggerte the value of a dedicated circuit to minimize noise. It will ensure you have adequate current which is 99% of the battle. but the noise on your AC line comes mostly from outside your house. My power regenerator has an oscilloscope built in and the power into my house has clipped sine waves and about 4% thd. After regenertion it has perfect sine waves and .1% THD.
Still, noise in a power supply isn't nearly as bad as inadequate current.
Jerry