Farming Professions
Nutritionist: Machines that take coop animal goods have a chance to double their output. (Machinery as in Mayonnaise machine or loom, but VPP doesn't try to keep track of where the wool comes from because the effort isn't worth it.) This doesn't apply to ostrich eggs. Requires Coopmaster.
Breeder: Coop animals are worth more when sold and their base price will be doubled. Requires Coopmaster.

Musterer: Machines that take barn animal goods work faster. Loom, Mayonnaise machine (only for ostrich eggs) and cheese presses will work faster. Requires Shepherd.
Caretaker: Requires Shepherd. Milk pail and shears take no energy. Chance for hay eaten by animals to not be consumed. The chance for animals to not eat hay is %35, and its evaluated for every animal individually and applies to all modded or vanilla animals. Requires Shepherd.

Machinist: Machines that take harvested crops work faster. Preserves Jar, Dehydrator, Keg and Oil Maker will process 25% faster when the inputs are harvested crops. Requires Artisan.
Connoisseur: Artisan goods are loved by villagers. Most villagers will love most artisan goods, but it wont automatically make every artisan good loved. If it's an alcoholic item(like wine, beer, mead etc.), if the villager hates the item or if the villager is excluded from this profession by the author, this profession wont apply. Requires Artisan.

Horticulturist: Trees grown in greenhouses will give iridium produce. This applies to every and all modded fruit trees as well. Requires Agriculturist.
Agronomist: If a crop is grown outside of a greenhouse, chance for fertilizer to not be consumed. Once you choose this profession, for every fertilizer you use outside of a greenhouse, each time its got a %30 chance to not be consumed. Requires Agriculturist.

Fishing Professions
Oceanologist: Attaching bait to a fishing rod will prevent trash from being caught. If the first catch is a trash item, the catch determination process is re-run up to 100 times, then the mod lets it go to prevent infinite loops even if its a trash. Requires Angler.
Artificer: Tackles last longer before breaking. Tackles will have now 40 uses instead of 20. Requires Angler.

Plunderer: Guaranteed treasure chest with every fishing rod cast. Requires Pirate.
Buccaneer: Treasure chests contain rarer and more valuable items. Some drops will be switched with others upon fishing these treasures with a rod. Full drops are explained on GitHub docs, since they're too long to list here. Requires Pirate.

Aquaculturist: Chance for fish ponds to produce double roe. The chance is around %50. Requires Mariner.
Trawler: Adding bait to a crab pot guarantees a high-quality catch. There's a %30 chance the output will be iridium quality, and %70 chance to be gold quality. Requires Mariner.

Recycler: Chance for recycled trash to produce various tackles. There's a chance that putting trash in recycling machine will output tackles. (It's usually %25 for the less powerful ones, and %10 for the more powerful ones.) Requires Luremaster.
Hydrologist: Chance for crab pots to produce a double catch. There's a %30 chance your crab pot catch to be doubled in stack. Requires Luremaster.
Foraging Professions
Arborist: Wild trees grow faster. Requires Lumberjack.
Shaker: Chance for wild trees to drop items when shaken. Full drops are explained on Github docs because there are too many to list here. Requires Lumberjack.

Sapper: Tappers work faster. All tappers will output %20 faster. Requires Tapper (the profession).
Orchardist: Tappers give double harvest. Requires Tapper (the profession).

Ranger: Forest forage worth more. Their prices will be doubled. Requires Botanist.
Adventurer: Non-forest forage worth more. Their prices will be doubled. Requires Botanist.

Gleaner: Crop seeds can be found as forage. Any vanilla seed may be found during their growing seasons in Forest, Mountain and Backwoods. (VPP will only affect vanilla seeds, but other mods can add theirs too.) Requires Tracker.
Wayfarer: Chance for forage to be found out of season. Any vanilla forage may be found OUT OF their regular seasons as well, for example a Holly may appear in Summer, Fall and Spring as well with this profession. VPP affects only vanilla forage on its own, but other mods may add theirs too. Requires Tracker.

Mining Professions
Metallurgist: Metal bars require less materials to produce. For all vanilla bars and for Furnace and Heavy Furnaces, the amount of ores are reduced by %20. Requires Blacksmith (the profession)
Ironmonger: Ores are worth more. And their prices will be doubled. Requires Blacksmith (the profession)

Ignitor: Furnaces work faster. Makes it so that any metal bar is processed %20 faster in both Furnace and Heavy Furnaces. Requires Prospector.
Crafter: Crafting recipes gained via the mining skill require less materials. The full changes are documented on GitHub. Requires Prospector.

Archaeologist: Artifacts can be recycled. Allows artifacts to be recycled via Recycling Machine. The full outputs are explained on the GitHub repo since there are too many to list here. Requires Excavator.
Mineralogist: All vanilla geodes hold the same items as omni-geodes. Requires Excavator.

Appraiser: Cinder shard nodes drop more cinder shards. In vanilla, cinder shard nodes drop 1-3 shards each. This profession changes them to drop 2-5 instead. Requires Gemologist.
Enchanter: Cheaper enchantment of weapons and tools. It'll allow you to enchant your weapons and tools using 4 fire quartzes for each enchant attempt, but you still can use prismatic shards too. Requires Gemologist.

Combat Professions
Warrior: Invincible monsters can be damaged. Monsters like armored bugs, rock crabs, mummies, or pupating grubs can be damaged. Requires Brute.
Berserker: Damage dealt increases at low health. When your health is below 1/4 of your max health, your damage is doubled. Requires Brute.

Survivalist: Length of positive buffs increased. The length of the positive buffs are doubled. Requires Defender.
Healer: Length of negative buffs decreased. The length of the negative buffs are halved. Required Defender.

Technician: Grants invulnerability during special weapon cooldown. You will temporarily be invulnerable to any enemy attack while any of your weapons are on cooldown with a cap of 4 seconds. Requires Acrobat.
Speedster: Increased speed of weapon attacks and cooldowns. Your weapon attacks will be double as fast, but cooldowns will also take twice as much. Requires Acrobat.

Assassin: Guaranteed critical hits against monsters with high defense. You will be dealing guaranteed crits against Metal Heads, Hot Heads, Dwarvish Sentries, Stickbugs and Rock Crabs. Requires Desperado.
Assailant: No cooldowns after critical hits. Requires Desperado.