Don't panic about money too much. Uber for Cairo is dirt cheap I've had rides turn up as 87p for looooog rides. Plus it's very safe. Additionally, food is dirt cheap.
www.sofra.com.eg/menu_choice_5.html
That is the menu for Sofra in Luxor. The 'expensive' mains cost about £5. Remember £1=22LE so your money goes a long way.
For taxis in Luxor if you stay at the Winter Palace or Pavilion the corniche is right in front of the hotel. Tons of taxi drivers will vie for your business. Haggle hard, don't like the price just walk away. They'll probably start chasing after you as soon as you do! Full day taxi in Luxor should run about 25 USD. IF you hire on the west bank after taking the 1LE local ferry you can get it much cheaper. To get to the west bank you need to leave Luxor to take a bridge far away so it adds time and fuel for them.
Cairo pass can be bought at Egyptian Museum, Pyramids or Citadel of Saladin.
Luxor pass can be bought at Karnak or near Luxor Temple (which if you pick one of the winter Hotels is next door effectively!)
Regarding paying upfront, you'd need to pay for flights and sleeper train. But you can leave the train until 2 weeks before departure. Hotels are payable on arrival. Regarding the cruise you'd need to pay a small deposit to the tour company you used, usually about 25% and rest on arrival.
To book the sleeper go to:
wataniasleepingtrains.com/ticket/index.html
I can help you figure out the site when you need to book.
Now, regarding photos. If you intend to bring a handheld camera you need to pay for a photo pass. However, mobile phone pictures are now free!
Let me know what other questions you have. Egypt is a wonderful country, sadly though if a mouse shits there the world hears about it and scaremongers. I feel safer there than in Manchester and London so I love helping people get to experience how wonderful it is. Especially before the tourist numbers really start to pick up. Now is a great time to visit it won't be this cheap forever there has already been a massive price hike since 2018.