Please don't block the bike lane or traffic or parking spaces, but use your best judgement; in that order.
Personally I feel a curb is a logical and physical barrier which protects you from the activities of the traffic way.
Getting on a curb means a car that hits you has already been slowed down by a 6 in. cement block applied up to 4 times (4 tires) against the cars momentum. Ever see a car hit a curb? Sure they can plow over it, but they definitely slow down, and change direction. When riding you have several options to evade, but when on foot you are much slower/less agile. Use the curb as a natural defense. Also, I'm not a law expert but I'm sure there are better legal protections for being off the road with regards to this matter.
Do you look everywhere and try to decide what everyone will do before they do it while riding. I sure hope you do, it will help keep you safe if you can anticipate situations, both while riding and while driving. If you remove yourself from the bike lane you become a non-player to those using the traffic ways. The cars don't have to decide if you might fall over while mounting/dismounting/precariously balancing while tying shoes etc. Like wise for bikers, will you see them when you decide to start? How straight will your line be when you do start etc. Even if you pull over far and look before you start up, you have forced others to do the extra work of thinking through possible scenarios and possibly slowing down, changing lanes or changing routes around a block where you are 'pulled over'.
If you are on a long straight away with no intersections and you can anticipate the traffic for the next 2 min, and you will only take 20secs then who cares. If you don't see anyone, but a car could pull up from around the block in less than 10 secs even though it seems dead you should probably just get over the curb.