new to TW bunch of questions.

what is a diff drop kit? and is necessary for my desired lift (1.5 inches)
biggest tires for 2011 double cab long bed 4x4 with no rub? (i removed front mud flaps)
can i put bilstein 5100s in the rear with no aal?
cheapest way to get 1.5 inch lift without compromising durability of vehicle?
are leveling kits bad for the frame or any other parts?
5100s worth it?
if i do get 5100s do i get them for the front and rear? and what do i set them to in order to accomplish desired lift? (1.5 inches)
im thinking of putting on 285/75/r16 tires do i need to adjust anything? mechanically speaking or just need to re program computer?
if i get 5100s do i need new coils as well?

thanks in advance for answering all these questions i know its a lot but im a newbie