Where do I begin with all of this...
So to start - no, under no circumstances should they "level the playing field" in terms of actual skill progression. This is the ONLY form of progression - no matter how fancy your ship looks, or how spiffy your character be outfitted - your skill will be the determining factor. Maybe you've got tens of thousands in gold stashed away, and maybe.. you've been lucky. Sure - you could regularly turn in 20+ chests that's great - but when that one scrappy vessel that you laugh at because it still has basic designs comes along and you hear their captain shouting orders as the sails turn and the broadside echos - you realize that for all you gold, you're outmatched.
I understand with the Alpha that people will be experienced with the game world as it is - and I'm not against a map re-arrange/scramble from alpha to release - but not at all after release. Introduce some new territories, sure - maybe even expand the map gradually - but it would be foolish to re-arrange the map.
Now here's the flaw in your thinking there - If they keep re-arranging it, what's the point of learning it? It's a skill to navigate, and navigate well, so learning the courses is a major boon for the seafarer and pirate alike. You'll know which routes are most heavily traveled (or should be) - you'll learn the places to hide, where to skip a pursuit, and where to run someone aground who may not know about an islands shallows as well as you. This is a Skill and needs to be allowed to blossom in the game.
Now - that being said, the next argument is that this causes division in new/old players. I argue against that point. Of course, some will be used to sailing with crews of experienced players - but I for one, even when friends were online, have been known to join random sessions with new folks during alpha invite waves to teach them some things. And before you say "oh that's a rare occurrence" - Let me posit this, veteran players have a lot to gain by teaching new players. It will get lonely upon the sea if no one can actually challenge you. So it would be beneficial, and smart, for veterans to teach new players from time to time (as I did, and plan to do).
I am all for new features, and changes to the world (Maybe based on world events?) but I'm against some means of "skill balancing" like suggested. I've never seen a game like Halo/CounterStrike/Destiny attempt to cripple players who have learned the ins and outs of a game just so the new guy joining the lobby doesn't feel outclassed. Heck, what would be the next step - aim assisted cannon balls?
To this I say, learn the map - like we have. It will take you time to learn, just as will knowing when to fire a cannon on the waves to hit where you'd like on a ship. Or when to use a blunderbuss, and when to use a cutlass - let alone how to use either. They're all skills, real player skills - not some experience bar that gives a buff - so take the time to learn them. Clean slate, once, sure - but not after release.