That's only possible in the 'Twilight of the Arnor' expansion. Double-click on that base, there you can check "allow auto-upgrade" and change also the built-priority.

Yes, this way avoiding some micromanagement. You can also build only hulls instead (constructors cost maintenance) and upgrading them the turn before they'll reach their designation.

But most efficient is to use everything you have ASAP. One possibility is to set a rallye-point to an auto-update station and construct a unique-named vessel and route this to that base using the governor - once the base is finished simply re-route these to other bases - lets you built out your bases with just having to use the planetary governor and (occasinally) checking the status of your bases.