This is a common procedure. The Crawford tube is usually left in for 6 months and then removed. It is not dangerous. You may have some pressure (sinus sensation) for a few days to a week. After that, you won't even notice it. This procedure is performed on children all the time.
General anesthesia is common because the areas along the nasolacrimal system cannot be numbed very well. Without general anesthesia, it would be very painful.
There is minimal, if any, bruising.
Most general ophthalmologist can do this procedure.