no
Check your blind spot if you are changing lanes. Sometimes it helps to know if you are planning on turning right or left next so you don't have to switch lanes later
no
It is illegal to change lanes while in an intersection in th state of Arizona.
blocked lanes
It depends how long the intersection is, how many lanes there are, and how wide the lanes are.
"Under a traffic light" implies that it is at an intersection. You are not allowed to change lanes while passing trhough an intersection, you must maintain the lane you are travelling in.
Yes, unless there are multiple designated U-Turn lanes for an intersection or freeway. (of course if they are not permitted, you don't period.) :D
yes and dangerous
There are five characteristics of an expressway. They are, must have multiple lanes, is divided by a barrier, each has vehicle restrictions, high speed traffic, and controlled access.
Yes it is
Yes, at least in Florida according to the drivers handbook. It's illegal to change lanes within 100 ft of an intersection also. I've never actually seen anyone get pulled over for it though.