Out of personal experience i can also say that ArkInventory (all in 1 bag thingy) can cause a alot of problems with addon related crashes / unresponsiveness.

What happend was that i bound my B button on the paladin to Concerate and all the slaves still had the bag open bound to it. It looked funny when tanking, and i didn't care to much at lower levels yet to see what my slaves were doing. So every time i openend the bags it would leak a bit of memory, and after some time, especially in instances where i had to tank i noticed the memory on the slaves going higher and higher. At some point they would reach around 90mb each, and start becoming unresponsive and sometimes even crashed.

So you'd do well to evaluate your addons to see if one of them might be having a memory leak.