Hmm, adding a keybinding for a workshop option? That requires a touch of modding.
If still interested: you probably cant reach all the vanilla workshops and wont be able to put shortcuts on some stuff, theres certain hardcode going on.
The folder DwarfFortress/objects/raw contains a reaction_other text file. open that in notepad or similar. First two entries are going to be milling seeds and cooking fat for a vanilla DF. You might notice the lines
[BUILDING:QUERN:CUSTOM_S] and [BUILDING:KITCHEN:CUSTOM_R]
Thats how those keybindings you want are assigned. It will support i believe ctrl+, shift+, alt+, but you'd have to dig the syntax up from somewhere. You can assign to any workshop task you might create for a mod workshop, and you could alter/add to any vanilla reaction exposed like this in your RAWs, but a great number of the vanilla shops and reactions dont appear anywhere in the RAWs, its compiled in somewhere. Your two examples for instance. wheelbarrow is carpenter, I know you cant touch carpenter, you'd have to give wheelbarrows to another workshop entirely (and write a custom reaction since there is no wheelbarrow reaction in the raws), rock pot is craftsdwarf and i know you can do some tricks with that shop since i've seen them modded. That particular reaction however....
Explore the reaction RAWs, try the modding forum for further help.