anyone hoping for changes to the region of france and iberia should give up hope, you should that for gameplay reasons they are made relatively easier for new players to play as the big boys and any thing that might weaken them would be looked down upon.
''Oh I am new player what a scary complicated strategy game. Let's play as something easy then...Castille, yes, in kindergarten I remember something about Spanish galleon. Oh God what it is? Rebels of Leon? Jesus Christ they killed my royal army. Well, sorry paradox, I gave you these dollars for base EU4 but I won't play it ever again nor buy dlc, it is too difficult. I go back to league of legends''
...well yeah if I were from paradox company I would also tremble imagining losing all this money.
...
You... are aware that France historically WAS the country strong enough to fight half of HRE since 1494 and basically in 1494-1815 period it received like 50 coalitions devoted to fighting it? Spain wasn't that OP, it just maintained the empire stretching on three continents while fighting Ottomans France England Netherlands and Morocco for mere 100 years before economical fall.
As long as in eu4 Spain isn't able to dominate area from Mexico to Argentina in 50 years and lone Revolutionary France can't beat coalition of GB, Austria, HRE, Prussia, Russia, Portugal and Spain - they are not as overpowered as they were in history.
And yes, I have once played as Netherlands while bordering hostile France...