action 3: (using a free action cube) - place / upgrade ship in new age and score VP againThe rules are confusingly worded, but I think the intent is that each age can only be "entered" once.
But the rules do say "Only the first ship in this age receives these points" So I think 3 is legal, but would not gain you the VP.
In the section about "deciding whether to place in the present ship age":
rules pg 7 wrote:
The first decision you need to make is whether you place your ship counter in the highest ship age presently occupied or in the next one up.The wording here suggests that the presence of ships determines what the current age is
The very first person who chooses this action must place his ship in ship age one. Once there is at least one ship in a ship age level then players have the option to place in the highest available level or the next level up.
You can never place your ship in a lower ship age level than the highest one presently occupied.
In the section about "placing your ship in the next age":
rules pg 9 wrote:
The first player to place a ship in a new age level earns victory points, which will be indicated in the ship age level.In this section suggests that the scoring isn't dependent on the presence of ships.
The rules have a similar issue around area scoring