This can already be done fully, with a combination of flags and orders.
Scenario 1. You don't want any colonists arriving at this time on a colony. = Tick the "stable" button on the civillian screen, and the population can only grow from it's own on world growth rate. If the population is currently zero, then you will have zero growth.
Scenario 2. You don't want any auto infrastructure shipments. = You flag it as military restricted, this in effect puts a civillian trade ban on all goods as well as blocking civillian ships from going there for any reason.
Scenario 3. You have a new colony that requires some infrastructure to get started and you don't want/have to use your own freighters. = Make a supply/deman order up and the civillians will ship it in for you to the specified amount.
Just usng combinations of the above will solve all the problems first mentioned.