Posted by a gardening novice!!!

Advice would be most welcome regarding my latest home improvement project. I
want to replace the stone flags in the lower half of my garden with turf
(what's the point of a garden without grass?!). So far, we have taken up the
flags and removed the large lumps of concrete/cement that have been left
behind. What now remains is a bomb site containing lots of hardcore and
bedding sand.

I would expect that the hardcore and sand will provide good drainage, so I
thought I would put a good 6" of topsoil down over it onto which I can then
lay my turf. Is this a bad idea? Am I really going to have to get rid of all
the hardcore & sand? Am I going to have to rotovate?

As an aside, if anybody has any good ideas as to what I can do with the
flags that I no longer need, I would also be interested to hear. Basically,
I want somebody to come and take it away. We only have a small car limiting
our ability to take it to the tip, and coupled with poor access to the road
and single yellow line outside our house, a skip wouldn't be ideal either.
Is it worth advertising it free to a good home providing they come and take
it away?

Thanks in advance, Pigling