DPS frustration

[AiharaMizuki]

Problem I have with BLM is the minute I am in actual combat and have to move all the careful planning and rotations fall apart

As many have said, myself included, BLM is more than just practicing rotation on a dummy. You need to actually play a lot of BLM in said EX trials for you to actually get better. It doesn't take "months" of dedication to do at least 3k dps. From personal experience that you can verify on FFlogs, took me 16 Laskhmi kills to go from 2.6k dps to 3.8k.

my own experience shows I can tank and do decent dps (for a tank) far more easily while holding aggro and not dying. This would indicate tanking is easier.

That's subjective. Different people can and will have different opinion. There are people, several who have already made a reply on this thread, that may find tanking hard but a dps class easier.

Also there are several people pointing out that the numbers on your fflogs isn't exactly good. Holding aggro, not dying and doing mechanics is arguably the bare minimum for a tank. A good tank can do all of that while putting out big dps.