i agree that this thread pertains to covers, not song writing.
my thoughts on covers are: the only reason why i play a lot of them is because people like them. i really do not care much about them, unless i learn something from it - song writing patterns, new scales, etc.
good luck learning new things with the tired old favorites people want (at my age, even classic songs and popular faves bore me).
next is, nailing a guitar sound is good and all, but if you go through all the trouble to get a certain sound, it is pretty useless, unless your vocalist nailing the singing parts too. i have heard bands who nailed the sweet child o mine sound, but their singer aint anywhere close to axl, so it did not impress any of the music geeks around.
another is, people who like cover songs are non-musicians, and they wouldnt know the difference between a les paul sound from a strat sound ... they wont also know the difference if you hit an Eb on a passing note instead of an E. they only know when you are out of key, extremely out of tempo, or too loud.
having said that. my take on cover songs is: as long as the audience loves it. some parts you have to nail note for note, some parts you can just do a sound-alike.
as for tone, the audience doesnt care about the specifics, so unless i am crazy about the song, i really dont care much about it.
and finally, you cannot please music geeks. they also comprise a small part of the audience, they usally do not pay to get in, they also usually do not order much, they also wont book you good gigs. so its ok for them to hate you really
