I agree with much of AliceD's well-cited answer, but here are a few extras.
- What part of the brain is actively controlling saccadic movement?
It is not clear how you would choose just one area of the brain, given that a whole network of cortical and sub-cortical areas are involved, and what you mean by "actively controlling". The superior colliculus is certainly a good candidate, but signals pass through the reticular formation of the brainstem to the eye muscles. In the cortex, the superior colliculus receives projections from the frontal eye fields and the parietal cortex, thought to involve guided attention. Munoz (2002, pdf) is a short review of this network.
- If this part were to be removed, does saccadic movement cease to exist and cause the person to go blind from not being able to look
- Additionally, is there a disorder which eliminates saccadic movement in some way?
It follows from the above that there are many lesions which would affect/remove saccades. As noted by AliceD, this does not mean the person will go blind. One interesting case reported a patient with eye paralyis (due to fibrosis of the ocular muscles) who made "head saccades" in order to scan the world in a similar way.
Gilchrist, I. D., Brown, V., & Findlay, J. M. (1997). Saccades without eye movements. Nature, 390(6656), 130-131.
Munoz, D. P. (2002). Commentary: saccadic eye movements: overview of neural circuitry. Progress in brain research, 140, 89-96.