Enjoy your fisherdorfs, peasants, lyemakers, potash makers, cheesemakers...I would hate for that to be the case, particularly when trying something is the only way to gain skill in it, as it is now.
Well the general idea was that your home civ would play a bigger part in it. You could request visiting master+ artisans come train your dwarves up to proficient in the advanced labors like smithing and jeweling
(this would take materials mind you and quite some time. Theory lessons and demonstrations), buy apprenticeship from other civs by sending your dwarves there and request specific kinds of immigrants who take X years to arrive based on how much training you want to give them, all the way to proficient. Intermediate labors such as making clothes would just require the dwarf to carry an instruction book until proficient and learn like they do now. Dwarves below proficient would stagnate until given the proper means to advance, anyone proficient or higher would learn by doing. Vital and simple labors wouldn't require training at all
Loosely based on the guild system and apprenticeship of old
Most apprenticeship suggestions basically just ask for free skillups, I wanted a little more depth than that to make up for it. Mind you, this would sort of apply to military dwarves. You'd need an elite from back home supervising sparring to get to 'great' categories in any given weapon class. This would also solve any problems with drafted civilians going too high and being unable to work anymore. Adventurers and other civ's elite troops could also be used, though this would require payment and good relations, respectively
To avoid artifact shenanigans ruining it all, only the master+s could make artifacts via fey moods. Perhaps the only way to become legendary. Possessions wouldn't count towards artifact limit per site or dwarf since those are just the masters of old completing their life's journey through someone else. Not really a problem with champions but while I'm at it, I'd prefer if said status required actual notable kills. A lot of them
You could of course use your own dwarves for apprenticeship once they reach master status or higher
Difficulty of starting a fort would be pretty much the same regardless of my changes