Question On Lag

If I make a floating text destroy/rebirth to follow a unit, will it make the game lag? Let's say I have a lot of them on the map.

Not if you destroy it. but im pretty sure theres a function for moving floating text so just move it to the units every .01 seconds

If you want it to be lagless. Just use the Timer Expires, with a never-ending timer. It's the least-laggy way to go about Periodic Events.