Cathedral - Is the market replenished by the player or by the bank?

The Struggle for Catan

The market is always replenished by the bank.

Note: The Cathedral isn't part of the regular card pool.

Merchant Guild - In which phase may I use the Merchant Guild?

The Struggle for Catan

The use of the Merchant Guild is not confined to a particular phase. Therefore, you may use the Merchant Guild at any time during your turn, even immediately after you have built it.