I don't think it was far off. In Leckie's book he calls their time in Melbourne 'The Great Debauch.'
No, he's not a character. The miniseries was originally planned to have 13 episodes focusing on 5 main characters, one of them a pilot, but they cut it down. You do see some corsairs bomb Bloody Nose Ridge in episode 7, though.
For me, the miniseries started off a bit slow but it's been getting better and better. The Peleliu arc was as good as anything I saw in Band of Brothers, and last night's episode with Basilone and Iwo Jima was very well done too. I love Band of Brothers, but at times it was a bit too romantic, a bit too polished, and had more of a 'Greatest Generation' feel to it. Nothing wrong with that, and they were probably more respectful since a lot of the men depicted were still alive at the time. What I like about The Pacific is that it goes where Band of Brothers wouldn't. They complement each other quite well.