As many of my ideas
here come from thinking about
@Ticio 's comments in other threads, I think it is worth I copy and expand them in here too:
As it is commented too in ohter posts of this thread, I think one of the biggest fails or Spain is its trade CUA is not that rewarding.
However, instead of proposing an improvement based on lenght of the trade route, my proposal would require intercontinental expansion. I think this brings forward Spain's strong focus on actually settling and governing the new explored lands, by setting up specific laws, governors, administrations, etc.
Treasure fleets were huge targets because they cummulated the wealth of all the continent in a single voyage. Internal trade routes would end in Veracruz or Cartagena (de Indias), and then the fleet was assembled and sent to spain (Cadiz, Seville), were it split again to the final destinations.
This gave me the idea of
increasing the bonus of treasure fleets depending on how much cities you own in the continents at the two sides of the route. (it could also be in non-home continent, but I think it balances better if you consider both sides). The "level" of the route would be the number of cities that is less in each of the two continents. So in example
- A route between a continent with 5 spanish cities and a continent with 1 spanish city would be level 1 (basic yield bonus), as one continent has just a single city
- A route between a continent with 4 spanish cities and a continent with 2 spanish cities would be level 2 (2x yield bonus)
- A route between a continent with 3 spanish cities and a continent with 3 spanish cities would be level 3 (3x yield bonus)
- An (international) trade route to a continent were Spain has not settled will lose the bonus. (0 cities, level 0, 0x yield)
I suppose it should be capped somehow so after a number of cities the bonus could stop or increase in smaller steps.
This will push expain to really want to expand into different continents for increased rewards. It will be a risky strategy, but a different gameplay style and with a reward that pays the risk. Also, as you increase the trade route bonus, you could also increase the pillage yield, as suggested in Ticio's routes, to attract piracy
Loyalty issues out of a "expand in at least two different continents" strategy should be handled (as Spain did), by religion. For Spain it could be considering doubling both the loyalty bonuses for same religion. And also the loyalty maluses for different religion. Spain's zealotry was not that much a matter of piety than of asserting the king's authority, as many foreign religions practices were associated -in some cases correctly- to external threats (islam to Ottomans, protestantism to England and France, and -in the case of Charles V, I in Spain - to nobles wanting to get independence / preeminence onthe HRE). The fact you need to negate this penalty and ensure your bonus would make the inquisitor bonuses more worthwile.
You may add, as commented in the other thread, a culture bonus for cities following only Spain's religion (something similar to the +culture of the monument in fully loyal cities)
As Spain relies in religion, it makes sense to give them a GPP bonus to found one. However, as commented in the other thread, I think it not needs to be straightforward to be one of the first founders and pick beliefs, as its gameplay is not that directly religion-focused, but more indirectly. I would make them have some kind of "late religion" bonus (in the same sense Arabia gets always the last religion, but not that strict).
My first idea on the subject is giving them a boost on GPP that increases with more religions being founded (or, at least, found), linking it to the Treasure Fleet trade route gameplay, I suggested giving them a big GPP boost if trading with a civ wich already has a religion. (maybe +3 or +5 great prophet pts. per trade route). A more simpler approach (sill linked to exploration) would be to give them a GPP boost or a big lump sum of GPP each time they met a civ with a religion. That is: Spain will have no direct bonuses to start the great prophet race, but will push as it discovers there are less options to get one, in order to reach the finish line before they run out.
Last, a pair of mission changes. To help with the "focus" issue in Spain's start, mission unloc could be shifted to Teology, but only with the faith production, and maybe an additional help to missionaries and religious units (e.g., as the name implies, +1 religious charge to missionaries, and maybe to inquisitors under Philip's LUA). Missions woud still need spain to focus in exploration to shine, so I'll keep the loyalty and science bonuses locked until that civic is researched.
And, I don't find this that necessary, but since many other civs are getting them too: Mission could be a good candidate for a "soft" culture bomb (as Gaul's mines have: get unclaimed tiles, but not these already owned by other civs).