Do individual Craft Skills have to be developed separatelyor is the one craft skill for all crafting.
So an Artist can craft armor as well as he/she can paint a portrait and Vices-Versa?
The Crafting skill applies to all crafting and repair. However, Alchemical Crafting skill feat is required to make alchemical items, Magical Crafting skill feat is required to make magic items, and Snare Crafting skill feat is required to make snares.
It is possible to specialize with the Specialty Crafting skill feat:
SPECIALTY CRAFTING FEAT 1
Prerequisites trained in Crafting
Your training focused on Crafting one particular kind of item. Select one of the specialties listed on page 267; you gain a +1 circumstance bonus to Crafting checks to Craft items of that type. If you are a master in Crafting, this bonus increases to +2.
If it’s unclear whether the specialty applies, the GM decides. Some specialties might apply only partially. For example, if you were making a morningstar and had specialty in woodworking, the GM might give you half your bonus because the item requires both blacksmithing and woodworking.
Specialty Applicable Items
Alchemy* Alchemical items such as elixirs
Artistry Fine art, including jewelry
Blacksmithing Durable metal goods, including metal armor
Bookmaking Books and paper
Glassmaking Glass, including glassware and windows
Leatherworking Leather goods, including leather armor
Pottery Ceramic goods
Shipbuilding Ships and boats
Stonemasonry Stone goods and structures
Weaving Textiles, baskets, and rugs
Woodworking Wooden goods and structures
* You must have the Alchemical Crafting skill feat to Craft alchemical items.