Am I Planning It Right?

yeah, atonement tanking isn't quite as easy as some people think, you pretty much need to be in a co-tank situation with someone that can match your hate levels. you can't do it very well solo tanking as you're being pressured into keeping hate and a good hit in your acc/haste build means you'll lose a good 300~500 damage worth of CE, that's normally enough to lose hate in a fight with good DDs doing their job (it's not very safe for everyone either if ***ever hits the fan).

even with a good co-tank and atonement tanking I've taken to using a defensive build for the last 25% of a fight, just because that's when anything's likely to go wrong.