What is the minimum I need to do to advance?
While heavily focused on by western practitioners - meditation is only one aspect towards the cultivation of the mind. If unsupported by the right morality and faith, your mind will be too troubled and unfocused to concentrate on the object of your meditation. In the case of Anapanasati and Vipassana, your object is your breath - but even as you're practicing under Mahasi Sayadaw's teachings, you probably notice that you start off focusing on your breath and noting phenomenons as they arise, but somewhere down the line you realize you've been swept away by a stream of consciousness. Only after the arising of many thoughts, do you even realize this has happened and you try to steer your concentration back to your main object and start once more with the noting. Before you're swept away again... 

Thus even if you are able to sit there for a long period of time with the initial intention of practicing meditation, it is difficult to advance.

The keeping of the 5 precepts is a good place to start. But perhaps by investigating the conditioned reality brought forth by the 5 precepts, you can realize for yourself their effects on morality and their qualities of non doubt, non remorse, and arouse sufficient investigative faith to progress.