How/why would a visual approach be dangerous? Only if you are bad at flying visual approaches, same could be said of non-prec approaches too surely.
At my base airport when a certain runway is in use I will generally knock off the automatics (A320), use the bird and hand fly a visual circuit from early downwind (subject to weather, which is 95% clear skies, calmish wind). This means I probably hand fly a visual approach A320 at least once a week.
I mostly keep autothrust in which increases safety I think.
The risks IMHO are 1) people who never fly them! 2) Not watching airspeed. 3) Not watching bank angle 4)Misjudging rate of descent on base/final and turn to final 5)Misjudging vertical profile overall. 6) Flying in bad viz/Wx in general 7) Flying in heavy traffic 8) Flying with tricky terrain.
The main benefit is surely going to be reduced time/fuel burn.
The IVSI is your friend!! The best hint I was given, which I still use, is just keep my left nut on the centre-line on approach. It works a treat.