2. Yes it's true, you can NOT trade on the market in winter.
Does this mean:
1. Just that a player cannot send a raw material cube to the market
2. Just that a player cannot move their cube from market to one of their buildings
3. Both 1 and 2
Ruleboook, bottom of page 6 wrote:
Trading on the market
The players can place the marker of the produced raw material in the market. The raw material can be bought for 1 work point and placed on any raw material icon on one of the buildings. A player cannot have more than 3 of his/her markers in the market.
It is the first sentence that makes me think that 'trading on the market' includes sending cubes to the market and not just gaining them as wild raw materials.
But since the Produce raw materials action clearly says the produced raw material can go either to another building card or to the market, I will interpret this as just option #2 above.
Which brings me to a new question:
If I spend a work point token, may I spend that work point to trade on the market?
If the answer is no, then does that apply to the entire winter round? In other words, could I get around that restriction by playing my work point token during the Builders' Guild phase?