There is just so much to deal with in that question, adn the related storeis, that my head spins.
Simple answer: generally no. And the ONLY time you should deviate is if you understand the reason the engineering, and then you would not b asking.
The story about the fuse being spot on 5A and therefore sounding better is just so incomprehensibly flawed that i wont even begin.
Fuses make no difference at all, unless they blow. Test it, blind and matched, yourself.
use the same value fuse.
If it blows think about the turn on sequence. Some amps (like everything i ever designed0 must have the low level circuitry stabilize for, oh, 60 seconds, before the main power is turned on or a fuse WILL blow. All this ought to be in the manual, which you have read, right?