Sounds like you've been out on the beer with Aussie fans. Ignore Bangladesh and Zimbabwe and take Murali's stats against the top teams and you'll find they're still very good compared to the likes of Shane.
Bowling alongside mediocre bowlers means that you'll get a larger share of the wickets, but it also means you'll lose a lot and take 20 wickets as a team less. It also makes it harder for a bowler to create pressure on batsmen if his teammate is leaking runs at the other end. I don't think it's...
It shouldn't be. Anderson is our best and most senior bowler, so Archer isn't expected to fill his shoes, he's our least experienced bowler. It's on Broad & co to step up, while supporting Archer as he learns about test cricket.