Put an 'isolated' cluster of pulsing xenia in there or a frogspawn. It might host that. I've never had luck getting a tank raised percula to host anything though. It seems like they're hit or miss.
I agree that a BTA in due time would take up the majority of your nano. Mine was relatively small when I got it and now can stretch to be roughly 10" across after a year. It takes up the middle 3rd of my 38 gallon. If you were successful with it, you wouldn't be able to keep much else.
As for the above article, I don't entirely agree with it either. I won't argue that A LOT of unqualified people buy anemone's for inadequate systems and for whatever reason, a lot are lost. From what I've seen though, the guys that hold their tank as a major priority in their life, are well informed and determined, with the right equipment, can keep an anemone that 'was healthy to begin with' for years to come. The key is to get one that's healthy. Then make sure you have good lighting (and don't be afraid to buy new bulbs), feed it and be sure it's a seasoned, stable tank. I'm past the one year mark with mine (knock on wood).