Some useful hotkeys (that I didn't find documented anywhere):

• W/S/A/D or arrow keys to move between rooms, or switch recipes in the recipe book
• R opens/closes recipe book
• T opens/closes talents
• G opens/closes path of the alchemist
• M opens/closes handbook/help
• L opens/closes legendary recipes
• U opens/closes upgrades
• Shift+click an ingredient in your inventory to throw it directly into the cauldron.
• Ctrl+click an ingredient in your inventory to throw it directly into the mortar.
• Rightclick a potion from your inventory to offer it to a customer immediately.
• The number keys 1, 2 and 3 are shortcuts for customer dialog options (1 sells, 2 haggles, 3 ends dialog)

Other useful information:

• Using the bellows makes the vortices rotate, but also makes your stirring more effective, so you move faster over the map with less stirring. So it is sometimes quicker to first use the bellows, then stir, then use the bellows again, instead of stir first, then use the bellows.
• While holding an ingredient, you can drop it over the cauldron to let it fall in, but you can also release it while holding it in front of the cauldron, which throws it in very quickly, which is sometimes faster.