@Cerez, please, make me sure, when is the breakpoint: when I will get a second part of a map or when I will come to a grotto?
If I remember correctly, the gameplay changes (in the background) when you get (accept) the second half of the map. This event is automatically triggered when you reach a certain point in levelling up (level 10), and next talk to an innkeeper.
Finding the grotto doesn't change anything, but finding what you're meant to find there locks you into a lengthy dialogue with a battle and some hard choices. So if your last save is a long while away, save as soon as you arrive to the grotto, and save again when the whole shebang is over and as soon as you have free control again.
My experience with this game (two attempts of about 24 hours) has shown that game has no problem with giving new quests (other than the main plot) until my character gets a "magic number" in experience level.
Yep, exactly. What happens when you reach that experience level (and find what you're meant to find) is that the state of the game world and the gameplay changes. Essentially things become more challenging, events speed up, and a war begins. After completing the grotto quest, the free-roaming quests will be unlocked again, but everything will have become more challenging from that point on -- there are more enemies you will encounter, because of the war/unrest that has started. If you choose to follow the main storyline (do what your father has intended for you to do), you will be locking yourself into a largely linear story, a linear series of events, and won't have that much time and opportunities for free choice and free-roaming.
Important to note that you can complete pretty much all the same objectives while free-roaming and doing your own thing, so from a gameplay perspective this storyline was really not necessary.
After tenth level Blaze can get some experience points only through: naval battles, storms and (maybe) main story.
I haven't experienced this. I think this lockdown applies only until you complete the grotto quest. It's intended to push you to pursue the game's main objective and storyline. But note that, in this game, your main character's progress and skills are not all that you'll need to focus on. You need to find quality officers and train them (a captain can't do it all alone), you need to upgrade your ships to be able to endure the dangers ahead, to earn/steal funds to keep sailing and keep your crew and ships well equipped and fed, and to deal with rising challenges/difficulties and fixed time limits for completing your business.
Pretty much the only time your main character's level and stats matter, actually, is when they are fighting alone. Otherwise more experience points earned only serve to make the game more challenging for you, gradually (and setting certain scripted events in motion).
It's important to me, because I like to develop player character in trading before the improvement of fighting skills, but game force me to do in other way. Playing as a merchant without gaining experience points is pointless (

) for me.
I completely understand that, and where you're coming from -- and I support it.
Do you know, how hard are these limitations coded and in which file(s) could I change it?
I don't think you will need to change anything, as long as you complete the grotto quest and choose
not to follow the main storyline.
But if you want to tinker with things, these events (lockdowns and starting functions) are defined in "Program/quests/story_line.c". (Just be sure to back up your original files before tinkering with them.)
I'm planning to develop a comprehensive patch that unchains the main storyline from the game, unlocks locked-down, fixed events, greatly expands on the dialogue/interactions (making even minor characters appear more alive, and enhancing the overall role-play experience), and makes the entire game free-choice and free-roaming. I found myself strongly disliking what the developers did with the main storyline in this game -- its rushed and poor execution. I think the game would have done much better completely without it, and pursuing the intended open gameplay it already had in motion -- perhaps not commercially, but certainly in quality.
For its open and free gameplay, however (even with the brief fixed main storyline interruption/annoyance), this is still my favourite Sea Dogs game, and I think always will be.
