Wow! I've never, never seen Hueguenot France develop! On the other hand, playing as England I've managed to completely avoid the English Civil War in 2 out of 3 GCs, too. Averages out, I guess.
I have seen an independant Catalonia or Catalyun, but it happened via a round about route. Spain was at war with England, France, Portugal, and Turkey and, for obvious reasons, not doing well. My English Expeditionary Force sieged and took Gibraltar (my goal for the war), then moved on and besieged Catalun for a bargaining chip in peace negotiations. A small Turkish force arrived to 'help' with the siege, and when the province fell it went into Turkish hands - the small force had a multi-star commander with it! Turkey then made a separate peace, keeping the province. Within a couple of years Catalun revolted against the Turks and became independant. Between independant Catalonia, English Gibraltar, Portuguese Andalusia, still-independant Aztec nation and no Spanish colonies or trading posts north of Central America or east of Suez, the Spanish did not prosper in that IGC at all!