I'm not asking for anti-blopping mechanics but for ways to make the game more difficult for experienced players. I really think the devs should add a hard mode.
I agree with your post except this quoted sentence.
The problem for me lies in the easiness and quickness of attaining a bit of everything, except legacies.
For instance, land grabbing CBs should only be available to characters with a certain trait (Ambitious) or that have more than X (between 12 and 15 would be a good range) of Martial. For religious land grabbing CBs the trait should be Zealous. This would solve most of the easiness of expansion to a large degree.
Claims should also be much harder to be fabricated with events that would force the player to make significant sacrifices or see the progress of the claim to be reduced or even starting from scratch. Another way to do it would be to treat claim fabrication as some kind of scheme with a time to setup and then in the end having a certain probability of success based on several variables.
The number of MaA should be reduced substantially as well as their maximum regiment size, because the player will max out much easily everything and fine tune everything than the AI and coding a decent AI for this game or any other very complex Paradox title is not something that is going to happen, due to personnel and hardware limitations. So the AI either should have invisible crutches or we must live with what it is.
At a role playing level, lifestyle perks should be much harder to attain (in my personal mod I quadrupled the number of points needed for a perk - 4000 - and make it dependable on both the main stat in question and the learning stat) and on average, finishing an entire tree should be the accomplishment of a lifestime.
Still on lifestyle perks some of them are too powerful by a larger margin. I understand the need to provide significant bonuses with each perk, but for example giving 25% to claim fabrication instead of a whooping 50% with a perk would still be significant but much more balanced.
Then we have legacies, which suffer the same malady as the lifestyle perks. Some of them are way overpowered, but here the effect is felt much more slowly given the pace that legacies happen in the game. Anyway, it would be good to cover them as for instance if someone wants and given the present values, at some point by middle game the player only breeds ubbermenchen for
every child conceived.
Then we have how easy it is to convert religion and culture. It should be given the same treatment as the fabricate claims action and the rebellions caused by different culture/religion should be dangerous to the player with random events supporting the story of each rebellion and thus creating a new emergent narrative while making the game and the internal management of the realm much more challenging.
Then we have demesne size that is far too generous allowing the player to get vast amounts of wealth that is used to finance growth, both territorially as well as in terms of carpet building everything. And again, the player will do this and max out demesne size much better than the AI.
Heirs should be harder to come by and descendency should be less assured than it is at present where a character has on average a good 5 or 6 children without any effort. It is interesting that fertility is more or less in line with what were the averages of those times, but children died like flies before reaching 10 and that is not reflected in the game. Also the pregnancy should be significantly more risky than in vanilla. To mitigate a situation where a character dies without descendants possibly forcing a game over being a tad bit heavy handed, have a decision available for the old character to attempt to forge a new heir at considerable expenses and risks. Obviously this new heir would always have opinion problems along his life due to the rumours surrounding his misterious appearance.
Finally the risk of death should be a clear and present danger for each player character. Events tied to dread, to tyranny, to popular opinion in the provinces, to control in the provinces, to the assassination scheme against the player, should pose a critical risk to the character being played, always keeping him/her on the edge.
This is what I have to say about the post with which I agree - except with the last sentence - and having implemented most of the measures I enunciated here in my personal mod I can say they work very well. Yes, gameplay is still on the easy side of the spectrum, but each game is no more a walk in the park and the emergent stories that arise keep my interest in each campaign much longer while always being a pleasure to immediately start anew after a few days off.