What stuff is account wide in game ?

[Markalus]

Just like topic. Currency, items, titles, etc.

[Catherina]

you mean the stuff from the founder pack?

[Markalus]

I mean all in game things.

[Darkrayne]

Nothing is account wide.

There's 'server' wide stuff though:

Adventure book completion
Mokoko seeds/island heart/giant heart/masterpieces
Achievements
Engraving unlocks
Ship upgrades
Sailors
Affinity
Skill/life/nature/stat potions
Most currencies
Cards
Titles
Your stronghold
Mounts (after doing mount unlock quest)
Pets
Lifeskills
Lifeskill tools
PVP rank

... probably a few more things.

Nothing is retained if you make a character on a different server and I do mean the specific 'server', not the region.

Nothing is account wide. Do not listen to people saying some founders items are account wide, they aren't. They can only be accessed on the server where you create your first character. People are using the terms server wide and account wide interchangeably but they are not the same thing.

[Anathema]

The founder mount is supposedly account wide