Hello Elayne ... cannot see any reason not to, except that it depends on the weeds in the original turf that you wish to turn and bury. Weeds like dandelion, arum maniculatum, creeping buttercup, and celandine, to name a few, could still come through if not buried deep enough. Lawn feed and weed may be needed in the future?!

I'm a bit puzzled by your question - I can't see the point of 'turning' turf and laying on top. If you've dug up the turf to turn it, why not remove it altogether?

I guess if it's a big lawn there will be costs involved in getting rid of exising turf... eg a skip.

Depends how the garden is - I always stack mine in a hidden corner, with the turf face down. 2 years later, its turned into lovely compost...

If your origninal lawn is nice and flat, then why not kill the whole lawn with glyphosate and re-seed it. If you dig the lawn up you will (as already stated) need to remove the perennial weeds and then re-level the bed.

To be honest. With proper care and attention removing turf (assuming the turfed area is as flat as required) shouldn't be necessary.

A good weed and feed, appropriate scarifying and other standard lawn care should return most lawns to rude health.

Rather depends why Elayne wants to do this - it might be that the level of the current lawn is too low?