My 2p worth, I like grass but hard runway is generally more attractive and easier to operate.

Re the hard surface, no real preference whether concrete or tarmac. Water draining properties are more important and don’t build it up side down like Odiham!!!

The key thing re old surfaces is to ensure the used areas are properly sealed so material is not dragged into props or engines. Remember you don’t have to have to prepare all current surfaces, only those that will be used. Markings can show non-prepared areas off limits.

Re airspace, I strongly suggest you maintain control but have good liaison with nearby facility to work out procedures, ATZ shape. CAA in any case will requires this.

Don’t forget you will need a massive local PR campaign to get local support. Include running local charity events etc. You will need historical use records in planning case; hopefully use was not ages ago.

And for nimby’s, pointing out airfield use maintians a green space with minimal disruption and is a local asset. An industrial estate, race track or detention centre may not be popular if rumours of those get around!

And good luck!