I'm not a high class concert pianist but I know a few...
Concerts are usually arranged by hall/orchestra managers (depending whether it's a solo recital or concerto) in collaboration with the artist's agent. Obvious the artist will be consulted, but practical stuff is handled by the agent.
Artist pays for air fares and hotel, usually. (Though they may be booked by the agent.)
They practise at home, as far as possible, and anywhere they can (concert venue, commercial practice studios, friend's home etc.) when away on tour. 4-5 hours a day is typical.
No, arrangements for filiming and recording are usually made by someone else. Sometimes a recording will be initiated by the artist though.
Don't know about memorising, never asked (that I can recall).
Fees vary A LOT. However, £2000-£4000 (UK pounds) is very roughly typical. Names like Lang Lang and Kissin will get a lot more.
They will almost invariably be asked to give a masterclass.
The hall usually provides the piano - though some halls offer a choice or 2 or 3.