can keepers kill creepers in same turn over and over again?
Disclaimer: I don't have this edition of Fluxx, so I may not have found all of the relevant keepers.

Yes. The keepers with creeper removal from this edition specifically care about being on the table. It only takes one of your plays to actually play a card, not to use an effect they provide. These "free" actions can be taken at any time (in between card plays) unless specified otherwise.

The relevant keepers are as follows:


  
  Excalibur: If you have this on the table, you may move one of your Creepers to another player during your turn.
  Holy Hand Grenade of Antioch: If you have this on the table and it's your turn, you can discard it along with any Creeper of your choice.
  Finger of God: If you have this on the table you may smite (i.e. discard) any Creeper. After smiting, you must put this card back into your hand.
  The Animator: Counts as the Finger of God if the real Finger of God is not on the table.
  



Excalibur specifies "one of your Creepers during your turn", so you can do this once per turn.
You can use this "during your turn", but only once because it's discarded, unless you have a way to recover it from the discard and play it again.
You can use this at any time between plays. If it's your turn and you have multiple plays, you can repeatedly play and use this card.
If this counts as the Finger of God, it copies all the properties of that card, so it can be used to smite.