Ha ha ha!!
I like the idea of toying with them - but if you REALLY want to mind-f*ck them, you may want to consider the following... [That is, if you want to waste, er, 'invest' the time...]
Flip-flop on 'em.
Make them think that you're "Sybil".
Go back to the Kingdom Hall for one meeting - if you can stand it. Dress demurely. Cover your piercings with cosmetics or actors' putty. Answer at the Watchtower study with an underlined magazine [get it from the person still 'in', if you can...] and be sure to greet everyone at the Kingdom Hall after the meeting is over.
THEN...
Repeat your first action - and I liked what you suggested:
"....i am going to visit the brother one more time, this time ima wear my thick black eye-liner, my emo/goth cloths and take my tattoed-chain smoking- gansta looking friend (who i actually like ) with me and instead of just driving thru ima go INSIDE and order, say hi, introduce my friend and let him call me "sweetheart, babe, honey" (as usually) and do all of this INFRONT of the brother, just for kicks.... then wait again for the elders... and...... "
Lather, rinse, repeat.
Two things are CRUCIAL to this succeeding... Be sure that only ONE brother/sister/witness is present when you're back in your regular goth self. Be sure that the whole GROUP sees you in your "Good Little Girl, Good Little Jehovah's Witness" mode.
And have an exit plan - how to respond when the inevitable happens - TWO witnesses will eventually be present when you drive up to that McDonalds in your regular goth self - though you can delay that by showing up at different times and different days - DON'T be predictable!
When/if they DO finally succeed in catching you as your regular goth self, then you can go into that whole "Gee, I've been so depressed lately; it feels like I'm falling apart!! Why weren't you elders there when "SATAN" was tempting me to become 'worldly'???"
The goal here is to give THEM a nervous breakdown while remaining sane, yourself...
Zid the She-Devil