MS SQL is a program to store & retrieve all sorts of data in a database structure.
Usually it is used in a network environment & not for capturing tv images.
Maybe the database part is needed for the capturing software but MS SQL is a little bit heavy for doing that job while
SQL lite could do the same job I think.
I cannot see any harm in turning of the MS SQL part (not uninstall) except that maybe already stored data will not be accessible anymore.
If you dont uninstall MS SQL but just start or stop the services related to MS SQL , you can do that without harm.