[abulmagd]

i will only comment on ur 3rd question as ur other questions are already answered by an expert simmer

instrumental landing system -ILS is the most common for landing approach and autolanding, but not all ILS systems are capable for autolanding so the pilots have to disconnect the auto pilot AP landing

ILS is categorized into 3 categories, CAT-I, CAT-II, and CAT-III

To perform an auto landing - in real not simulations , the runway RWY, the airplane , and the crew have to be certified for autolanding or for CAT-III
for example if the rwy and airplane are certified for CAT-III and crew is not , the plane will be denied from performing to autolanding , so some airliners are puting certain pilots on board to only satisfy the certification requirements

now when does the pilot disengage the AP

the pilot disengage the AP whenever he wants but before the descision hieght DH or DA which can be found in the airport chart, in MSL mean sea level and in above rwy values , ya3ni for example i have here the chart of cairo airport HECA , rwy 5L has elevation of 190' above MSL so the DH is written as 440'(250')

CAT I is having DH of 200 or 250' feet from the rwy

CAT -II is having DH of 100'

CAT III is having A, B, and C subcat. all of them are having no DH but they are classifies according to the RVR or rwy visibility range
only CAT IIIC can autoland without visibility of the rwy

CAT iiib , the pilot has to see the rwy above 50 meter from the rwy otherwise he has to perform TOGA to be rerouted to another airport

CAT IIIA is having RVR of 100 meter

in CAT IIIC the pilot doesnt disengage the AP after landing as the system also provide guidance to aircraft on the rwy itself

when u r performing autolanding , u should engage 2 APs at same time as backup for the other one in case of failure

so what if the pilot didnot disengage the AP, capable airplane in a CAT-I rwy, will it autoland?
MOSTLY yes

Tayeb leih el soda3 dah ?
because the answer is only "mostly yes" not "always yes", to ensure that the airplane will land on the rwy with probabilty less than 0.000000001 to land outside it, as i think ILS is liable for interference as it carrier frequency is ranging from 108.10 MHz to 111.95 MHz which is so close to FM radio broadcasting frequency (the FM freq here in egypt ends at 108 MHz and i think many other countries are the same) so think of radio glitch at 30 feet off the rwy, can fool the AP to make a big correction off course at this low altitude

I hope this answers ur question and sorry for using english but it makes it easier for me to discuss technical issues