Line after line of garbage, frankly.
Imran, the 2 Ws, were swing bowlers. They took the pitch out of the equation. Had they been seam bowlers of the McGrath type and were able to be as successful, you may have had a point. In reality, they were much better at home than away.
Warne was better away than at home, and that is precisely because his home pitches did not suit his bowling, save Sydney. Warne's record in SL, on those pitches, is incredible. He outbowled Murali head-to-head there when their teams were at their most equal - the SL batsmen are imperious at home and great players of spin. The 04 series was owned by Warne.
Even more nonsense: that the PM caused Murali to bowl badly. The assertion that it is harder to bowl spin in Australia is not based on the fact that Murali did terribly there but that basically all spin bowlers did terribly there. It is a place where spinners, even domestically, even Warne, struggled. The two best places in the world to bowl spin? India and Sri Lanka.
Of course you'd want to look at common opposition: it would take out Murali's worst record (Australia) and also take out Warne's best (Sri Lanka). It doesn't need any further explaining why that would be disingenuous. See, it is pretty easy: Warne was clearly better than Murali away from home. Murali averages closer to 30 and strikes 60+. As aforesaid, Warne averaged even better away than at home.
Your point re his team composition and his own bowling load has been brought up several times. Bowling by yourself, at the opposition, also means getting more wickets, in loads, which aids your average. Although it is true that Murali had responsibility to defend more, he also had the opportunity to bowl to more batsmen (he came earlier on and bowled many more overs). These things even out, they're not simply/solely a disadvantage.
Murali is more successful in SL because the pitches have been doctored to his strengths. That was the smart thing to do, that was the right thing to do. Having your own batsmen put up good totals, etc, is fine, but you're exaggerating it greatly. That affects your win/loss record more, but not so much your ratios. In the end you have to bowl out the opposition regardless of how many runs your own batsmen put up. Ironically, if they don't put up enough the opposition may not have to make as many and Murali may concede less runs on aggregate.
Against India, Murali played more matches, Warne played more innings. The fact that Warne played several series injured more than counterbalances the fact that Murali had a bad last series. And even if he did, so what? Do we discount it? Warne had a very good last series and could have had an even better one if he wasn't injured for the Test where Michael Clarke took 6/9.
Warne wasn't horrible in WI, see... you don't know what you're talking about. Warne had good/great series home and away against WI in every series bar 1 away. And that series was when he had huge shoulder injuries. He was having trouble against everyone - he averaged 55 in the Ashes before the WI series that taints his WI record. Since he only had 1 other series away (avg 27, sr 55) it makes it look like he had a problem there, against them. At that time he was basically learning to bowl all over again. This is well documented.
Of course it is, it touts your "Pak bowlers should get extra credit when bowling at home" argument.