Many of the speakers don't talk about the expansion of people, they just mention expansion of the building activity.
Regarding the maintenance of the buildings, they are being very clever here. They are going to have a detailed manual and provide training to ensure the congregations have a scheduled program of maintenance. Rather than let the building run down to a stage that it requires a number of updating at the one time (and therefore would be considered a major renovation for which the Society would have to pay) they will, no doubt, require modifications at a certain point in time. That might be repainting in Year 3, replacing carpets in Year 4, servicing electrical items in Year 2 and so on. Doing it this way means that the Society will not fork out the money but expect the congregations to finance these.
They are going to train the brothers in the congregations to carry out work such as Electrical and Plumbing. I don't know about the US laws but here in Australia qualified and registered Tradesmen can only carry out these duties.
I love the way that they give very little explanations as to why the commercial building type was more desirous than previous designs, yet they expect everyone to support the idea because the GB said so. They even pretend that there was some sort of democratic process to decide on the design.