Please don't forget the fact that you have the privilege of being encased in a few tons of steel with multiple safety systems. When doing your moral calculus and weighing how many lives are worth risking to save time, please remember there are other people on the road who don't have that privilege. Cyclists have to be constantly aware of cars breaking traffic laws if they want to stay alive, and they are not as visible as you would like to imagine.

If there is a non-zero chance of causing an accident and harming someone by breaking traffic laws, and the only benefit is saving time or not annoying residents, how do you justify that?

I justify that because I am not an absolutist. If you're really going for the 'what price a life' argument, unless you're giving your entire income and free time (excluding enough to keep yourself alive) to a relevant charity (say, clearing minefields), you also don't believe in 'any-percentage-over-zero-is-too-high'.