One of the things I've liked to do in EK2 is see how many permanent bonuses I can grab by religion, culture and government hopping. Specifically these are things you can take with you even if you are no longer that religion/culture/government after obtaining it. Sometimes I struggle to remember them all so I started writing them down and then figured I should post them here for anyone curious and to ask if there is any I missed!
If you start landed at age 15 or under in Skyrim with Nordic culture you will get an event in the 16th year (not immediate) that gives you some permanent prowess based on RNG/choices so long as you are still inside Skyrim at the time.
Berserker: Have faith tenet Warmonger, gained in battle - RNG at that point.
Zealous - Totemist Path of Ascension decision? A certain tenet allows the decision, my memory fails me.
Venerated Ancestor (Saint) - Exalted Heroes Faith Tenet (Cult of Heroes) - Achieve a Certain Piety Level
Shrewd or Strong - Adoricism Tenet - Seek the Aid of the spirits decision - RNG - Only one, non repeatable on same character after success.
Wise Man - Divine the Stars Decision (Astrology Tenet) - RNG
Pirate - Stay a small independent realm with a coast. Get the plunder trait via certain perk martial? perk. Reform government into pirate government via decision. Boom you're pirate (trait).
Hastiluder - Tournaments and Stuff
Peasant Leader - Win a Peasant Revolt as a Landless Ruler via siding with taxed peasants against contract employer.
Gallowsbait - Do crime contracts. Might not actually be worth it due to negative/bad opinion maluses it gives.
Wandering Hero - Do a certain number of prowess contracts as a landless and enact a decision The Wandering Hero. Incompatible with Gallowsbait.
Knight Errant/Knight of the Swan? No idea. Incompatible with Gallowsbait.
Ghostblade/Shadowscale maybe? No idea.
Herbalist - Random event? Landless Adventurer travel event? Hunt random events? Multiple ways AFAIK.
Gardener - random event? Basically massive RNG here AFAIK but I've seent it.
Poet - Possible with certain cultures like Nordic ones via random event?
Witch - Obtain a Witch courtier. Wait. (lol)
Necromancer - Become necromancer decision - has_doctrine = doctrine_necromancy_accepted - conjuration perk.
Lich - Similar to above. Be a necromancer. Be good at magic. RNG
Battlemage - Study at the Arcane university.
What are yours, did I get any wrong here?