In an effort to make the game more player friendly, what if it was possible that if you logged out in a crafting/gathering class, in that class's guildhall using a special option your PC would in effect be working around the guild as an apprentice. Because of that, he'd get a fixed amount of SP when he logged back in based on how long you've been offline.

For example, if you could gain 1% of what you need for the next level every hour, you could level up that class in about 4 days. It's not a lot, but every extra bit helps.