I haven't been successful hand-training my birds it's only been a week) but do you recommend me taking them out of their cage (just leaving the cage open and letting them out freely) to stretch their wings a bit and explore the house or not yet?

NO NO NO do not let your keets out of the cage without being hand trained. If there was an emergency you could not get them to safety.

I give full instructions on hand training here -

http://www.lisashea.com/petinfo/articles/bird_hand.html

follow it daily and be patient. Your keets will come out soon enough, when it is time.

As Lisa said, hand train them first. I have finger trained many birds but Lisa's instructions are the best I have seen and I like the process it describes. I did mine a little different but her way seems the least traumatic for the bird. Years ago I had one escape and boy was it hard to get him back in the cage! He finally got tuckered out and I was able to pick him up (did not know what else to do) and he bit me but good!

Thanks Lisa and getlow! I was on the verge of letting them out since every time I open the door (which is very seldom), they chip like mad. Don't spoil 'em, eh?

Just keep working on the hand training, it should only be a few weeks before they're ready

Keets can really hurt themselves if they are loose and in a panic and afraid, so it's really best to wait until they are calm and tame.