I feel like it would be a lot of fun if the professions had some sort of leveling system to them. So, for example, a brand new chef shouldn't be able to cook the same meals as someone who's been one for a while.
Suggestion 1: Lock higher tiered meals behind a level. "To cook Cactus Juice you need to be level 10".
Level 1 Chef can cook meat, and you gain XP from cooking it until you hit level 10. From that point on, you need to cook higher level meals to progress ETC ETC.
Suggestion 2: Give chef's a low chance to create "Rare" meals. For example, if I'm cooking 100 meats, I could end up with 97 cooked steaks + 3 rare cooked steaks, which would heal for a bit more HP.
Different crafter upgrades like Black / Cursed could also be locked behind a certain crafter level.
Medic could have something like Nin Online's "Jutsu leveling system" for their heals. Healing X amount of people would upgrade their heal in some way. Maybe less energy cost? More healing? An extra tick of healing? Longer reach on the healing? Or maybe even give them an option. Once they hit like 500 uses on their heal, they have an option to choose an upgrade for the skill. Like choosing one of these things. Maybe turning the skill into an AoE? Longer reach? Being able to cast it while running but for a lower amount of HP?
Just some ideas to making the profession system more fun!