Last I wanna share a curious bug that almost freezes my game and force me to disable the addon. Anytime I add a (Citadel Crossbow [of the Fireflash]) my fps go from 75 to 22, and It's on a paladin, paladins dont even use crossbows. I noticed everytime I put something in my bags the addon takes the math and my fps goes from 75 to ~22 for a while (3 to 7 seconds) and is think it's internal and also think it's fine.
I'd rather not have to manually re-do all the settings for all my addons in-game unless it's absolutely necessary (since I don't have memorized what the exact settings are I use, so I'd have to take screenshots of them all and then remake the settings to match the screenshots). So I'd rather get some more input about this problem before I try troubleshooting it that way. 

I've been having what is apparently a scaling issue caused by inflated secondary stats on some Wrath of the Lich King items. In particular, my Highmountain tauren warrior leveled through Northrend and picked up a green, iLvl 87, 2h sword. All of the secondaries were in the +25 to +30 range, and the Dugi Gear Advisor decided it was better than the heirloom 2h axe I was using. So I went ahead and equipped the sword.
Anyway I will go ahead & download the Twitch app like everyone's saying, but I still need to know whether my in-game addon settings will carry over automatically, or whether they'd return to default same as if they'd all been uninstalled in the curse client then reinstalled from scratch. Because if it's the latter then I will have to take screenshots of the settings on all my toons BEFORE I install the addons thru the Twitch client.
Determine the gear stats and armor type you need for your new character. For example, a paladin requires Strength as their main stat, and heavy armor (the armor type) will scale as the character scales if they are initially unable to wear heavy armor due to being a lower level. Your optimal heirloom gear set will feature the same main stat as your starting gear.
Anyway, there are no more shortcuts. There are no more "Tricks". It's just straight questing now since Blizzard nerfed other methods of leveling. You can still do dungeon spam, it just won't be as fast. You can still do BGs, it just won't be as fast. Just about the only alternative way to level that rivals questing is Pet Battles(which makes ZERO sense).
But now, the Gear Advisor starts popping up, trying to get me to put the old 360 version Ring #1 into Ring #2's slot, since iLvl 360 is better than 350. Except I can't do that, because of the "Unique-equipped" modifier. So I click "Cancel". And then the window continues to pop up after every action my character takes, over and over and over, until I get rid of the old ring by vendoring, scrapping, or destroying it.