To do the "From the City of David to the Western Wall", do i need to do the organized tour (only at 11 am) or is it open from till 5 pm?
You do not need an organized tour. You can visit on your own. Make sure you have a map of some sorts - paper or on your iPhone. You can download Jerusalem city guide from Tripadvisor. If you feel uncomfortable in foreign cities on your own then get and organized tour.
We had a guide with us for all the days. There is a lot of history and hence always helps to have a historian talk about it.
There is so much history and depth to the City of David and the Great Wall, depending on what you are seeking? If it is just sight seeing tour you could easily do it yourself if you like to hear, see and know more details of the ancient history an experienced guide would be a recommendation- enjoy!
I would do the tour as it adds a lot to what you can see. I thought there were a few tours each day.
Get quick answers from City of David National Park staff and past visitors.