Regarding nr.8
If a TOW is limited by an obstacle in 2nd segment, it means that the aircraft has to do better than the normal 2nd segment climb. If it is a twin then normally it needs to do 2.4% gradient after T/O if one engine fails. If there is an obstacle in the flight path it needs to clear that obstacle by 35' net gradient, and it means that it has to better than the above said 2.4%; otherwise it would not be an obstacle.
There are two ways of increasing the gradient: One is to make the airplane lighter for T/O, and than we are TOW limited for that obstacle. The other one is to increase the T/O speed, which is not always possible, first due to increased stopping distance in case of abort, and the other thing is due to the higher speed, more time is spent on the rwy and it in turn brings you closer to the obstacle you are trying to avoid in the first place.
Also by using a lesser flap setting for T/O increases the gradient but requiers a longer T/O run.