1 i don't
2 glad we agree on something.
3 nobody would want him to do it instead of him but loads of people still want to hear him sing it just cause he can (or in reality: could two decades ago) hit high notes. his voice is nothing special imo. heard better heard worse.
4 i could not disagree more. his voice is ace. fuckin awesome. both AC/DC singers have been epic imo.
5 yeah it sounds the same and if you're going to an AC/DC gig to hear him sing the old shit, that's a good thing. i think it's still pretty damned powerful. and again could not disagree more. i think his voice is ace.
6 it'd not be as good as hearing Axl sing it but it would still be very good to hear him sing songs like: Garden Of Eden, Nightrain, YCBM and more.
7 his range is as wide as ever but his voice is clearly not as good as it used to be. it's raspy cause Axl tries very hard to keep it raspy and not cause it's his natural way of singing like it used to be. 2001-3 voice fitted a lot of the new songs better the current Axl or the old school Axl and those that did not, the old school Axl could have done a better job on. that's just my opinion though.
3 - agreed, heard better, heard worse. I like his strut though.

4 - like I said before, both of their voices are good for the music, but neither is an overly impressive vocalist. Not at all.
5 - It's not as powerful as it was though, and really, he has no range. Mick Jagger sings better now than he did 30 years ago, his voice is deeper and stronger. That doesn't mean he was ever an impressive vocalist though. (I use Mick as an example because one, he's old and famous, and two, I personally love him.)
6 - Maybe Nightrain. Maybe. You wouldn't be able to understand a word of Garden of Eden if Brian Johnson sang it, and Brian Johnson doesn't have the voice to cover You Could Be Mine.
7 - The pre-GN'R stuff doesn't sound particularly "raspy", so it's very hard to say that's Axl's natural way of singing. (It's not Brian Johnson's natural way of singing, either.)