Yes, the kitchen is the oven. There is also already a model for the pump, however with a somewhat provisional texture (I think - which means that somewhat substantial changes could be made to the pumpjack if we deem it would look better. The pumpjack is from Matthias).

> I think it should rather be one building for tools (smith or sth) and one for vehicles (workshop ). It seems strange that both buildings can make vehicle and tool sized objects.

The original thought was this: In the tools workshop the player should be able to build all the basic tools he needs for mining - so this includes tools like shovel, pickaxe, ladder & co but also the lorry and some very basic explosives. Cannons and other big vehicles would be build in their respective workshop then (armory, shipyard). So the constructibles are not ordered by object/vehicle but by their purpose.
I however don't see the big problem with the lorry and other vehicles being produced in another building than the tools workshop.

Armory and tools workshop are more of a balancing than a design choice. As Newton said, tools are needed very early in the game but we don't necessarily give the player access to weapons as well. On the other hand another building is not that much effort and after the initial costs you can use it for free. Another aspect might be that all the weapons are flooding the production menu of the tools workshop.

I don't think it's a bad idea to have a seperated building for vehicles but only if there are more to come. We have the catapult, the cannon, the lorry and the airship so far. These are splitted to the armory, tools workshop and shipyard. Your container ideas might do to broaden the collection of vehicles but before we make that building we will have to think about a reliable concept of these vehicle parts. Otherwise you will end up with a building just for lorries, catapults and cannons. In a regular settlement scenario, just the lorry is needed and you force the player into constructing a whole building just for lorries.

> Spinning wheel / loom seems to be an incredibly specialized building regarding that all others are generalized buildings for one game concept.

On the contrary, the buildings are generally seperated into two parts: processing and finishing. Finisher are all buildings that produce usable objects (workshop, armory, chem lab, ...) and processors are just intermediate steps, taking raw materials and processing them into something more refined. Processors are in fact very specialised:
Sawmill: the only purpose is producing wood.
Mill: Only flour.
Foundry: More or less only metal. The gold part is somewhat minor as well as the new loam production.
Weaving loom: Cloth. Cloth is a general material . For now you will need it to make airships and balloons.