Yes, it features a dust and moisture-resistant design along with a fluorine coating on the front element to repel water and oil.
No, it uses an internal zoom mechanism, meaning the physical length of the lens does not change, which helps maintain center of gravity on gimbals.
Yes, it is fully compatible with Sony's 1.4x and 2.0x teleconverters, allowing for a maximum reach of up to 1200mm at f/13.