I am going to answer a few points raised by Ashalia in a private message, for future reference:
France starts with low naval force limits — yes. In vanilla they count on six, in the mod it's five. The minute difference lays with how naval force limits are modified: the land slider decreases these, resulting in higher costs for over limits navies. France starts with only two coastal cores in the Normandie and Caux. The third one, Languedoc, isn't capital-connected: so its worth, in force limit terms, is divided by four. If the French player was to conquer Berry, connecting Languedoc, he would increase naval force limits to eight. The French land slider setup hasn't changed, it still sits at +2 land.
I don't see a problem with the starting French naval situation, but it can be argued that the English advantage is perhaps overwhelming, compared to other naval nations: they will put down to sea twenty nine carracks in vanilla, twenty eight in the mod. The game assigns starting navies according to initial force limits, the English reach up to fourty two. England's tax base almost exclusively lays in port provinces, their force limits are therefore incredibly high. I believe that the English coastal tax base may be overstated in both vanilla and the mod. The British isles and Spanish Iberia count the same number of provinces.
Due to the high number of English provinces, Albion will almost certainly a) dominate the Curia (number of catholic provinces) and b) any initial naval confrontation, even in the Mediterranean. There was a similar problem with the Japanese fleet at the start of the grand campaign in very early "Divine Wind" versions: their fleet would be gargantuan due to how their tax base is distributed and the engine's starting calculation. That issue was solved, in vanilla, by assigning an arbitrary Daimyo's naval force limits reduction (a hefty -50%).