This topic hurts to read. There's misinformation across the board. Sadly, the OP is more correct than he's given credit for since the reduction in Parry Rating to Parry percentage.
I could say simply, "read the guide," because that essentially sums everything up. But I'd rather lay these myths to rest directly without info-babble.
You don't Dodge attacks from behind. Period. Players just don't do it (mobs do, however). Go find any level 5 mob, turn your back to it and stand still, then type /combatlog, walk away for a half hour. Open up your combatlog.txt file in your WoW directory, hit CTRL + F (find), and search for "Dodge."
However, feel free to search for "Miss." That should be pretty high.
Parry does technically increase rage generation. Because Parry grants you a counterattack which speeds up your swing timer (not technically Haste), you usually get your next hit in significantly faster and get the full rage.
Stacking Block Rating doesn't hurt you. Ruthlessman posted that Block Rating is harmful this on page 3, and I've been tempted to post this as well on other forums -- it's basically a semantics game. As he clarifies, stacking Block Rating at the expense of Dodge or Parry is what hurts you.
His phrasing wasn't all that great, but what he's saying is true. Block Rating is essentially a dead stat at the moment, and choosing Block Rating items over other tanking stats is hurting you.
Then again, if you can somehow stack over 100% avoidance/block rating and keep a respectable amount of health, that's fine.
25% block needed? Die. This myth is frustrating to read again and again. Moreso for people like Satrina and other solid posters who have to keep repeating themselves in the hopes the rumor will finally die.