I have been riding on Ballona Creek for several years now, from Culver City to Marina del Rey, every single day, day and night, light and dark... I have never had any problems, other than occasional fallen tree branches and floods during very heavy rain (happened only last year).
IMO, Ballona Creek is an underutilized bike path. Most people are concerned with the projects west of Centinela, I have never had any problems. On my 14-mile round trip daily commute to work, I enjoy exercising on the relatively easy bike path, I watch the Canadian geese, ducks and the Pelicans chillin' like Bob Dylan by the creek, while cagers suffer in nasty LA traffic.
If you live or work in the area, I strongly suggest that you give Ballona a shot. I started with 1-2 days a week, now I'm hooked!