How to determine if the Non-Player faction add a base/casino or the 6 resources?
As always, if it isn't specified, you go to 8.1.2. Procedure Guidelines. This instructs you to first place friendly bases whenever possible (with a few exceptions listed i.e. only 1 base per province for Government). So you would first place bases (where allowed by stacking rules), once a faction can not place bases anymore (due to stacking rules or exceptions from 8.1.2.), if they have cash left over they will exchange for resources.
8.1.2. Is the go-to rule if you cannot find a process specified (i.e. Propaganda round processes, priorities for event cards etc.).