I'm... not fathoming the problem in issue #1. you have so much time before the overcharge that as long as you're hitting everything before it you'll have good threat, and when overcharge happens you just click. The hitbox for the overcharged one is giant. You almost can't miss it. When a new one spawns, focus damage on the new one.
Issue 1: I would recommend if you are the add tank (which pretty much as a pally is what we are in that encounter) that you initiate the pull with a avenger's shield on the adds, drop a consecrate and then run in with hammer of the righteous (I have mine glyphed to hit an additional target) then let the Boss tank pull Emalon off you. At that point you may have one add that's not glued to you, if that's the case find it and toss a Righteous Defense at whoever it's targeting unless it's the Boss Tank in that case use a Hand of Reckoning so you don't end up yanking Emalon over. When tanking the adds I tend to put my back towards the raid and face the mobs out from the wall, when an add spawns it will usually go for a healer you can then RD again to pull the mob to you. As for the overpower the add get's huge and you should be able to just tab to the appropriate one.
For Emalon, I run in - pull with Avenger's Shield, drop a Consecration (picking up the boss as well) and then Hammer of the Righteous and finally Judge whichever didn't get hit by hammer. Then begin a normal 969 and tank all four with the boss as well for a few seconds. Once you're ready, call for the MT to taunt Emalon off you (make sure he doesn't use RD, heh) and you're good to go. From then on, just HoR and then AS any new ones that spawn.
You can greatly minimise the amount that spawn by simply cycling Holy Shield rather than doing a rotation except when one gets overcharged, then just do 969 with him targetted the whole time. This way you should only kill one or two extra before the fight ends rather than constantly having to grab new ones.
As for the Death Knight guy, I drop Consecration under him just as he's about to start this phase and immediately go into 969 once he's attackable. Once Army of the Dead is up, mash your Holy Wrath button for all it's worth - with Consecration and Holy Wrath, you should get at leat 5k threat on every one of them instantly. Holy Wrath is definitely your friend here because it doesn't stun but it still does Holy damage on them
1) Two things: I aim for the first mob at the right, Avenger Shield him, and while the shield is flying, I aim the first mob on the left and Hammer of Righteous when in range. There is one mob that won't get hit, so I Hand of Reckoning him and put him in place with the others.
The second part is the MT part. I had a hard time trying to get adds in one run 'cause the MT decided to put his back to the wall (and then kept complaining that there was an add there.) Second try, I said to put Emalon's back to the wall. After that, I could pick every single new spawn very easily.
2) I completely ignore the adds on P2 of Black Knight. I drop a consecration while he's summoning the adds and a Holy Wrath at the end and then start kiting him around the star in the ground. Pretty much like the add in P1, they seem to not have an aggro table and randomly jump into people. A mage is usually smart enough to see them stunned by Holy Wrath and drops a Frost Nova. DPS these days are so high, Black Knight dies with almost every add still up now, so it's just a matter of walking away from the explosions.