Blinking like Fade up/Fade down? Or cut up/cut down? or a mixture?
You can use just soft text or you can use text(RGBA mode) with axis for key.
Do the keyframe for 1 cycle of up down, and a keyframe for space on transparency channel. Then select channel and adjust the EXTRAPOLATION in the channel editor to CYCLE.
Flame/Smoke Editor
Check out the Premiumbeat Smoke Blog
http://www.premiumbeat.com/blog/category/smoke-2/