Obsession

At Step 1 (Rotate Service) after turn 1 you move servants from your Servants' Quarters to Available Service and move servants in Expended Service to the Servants' Quarters to rest; only servants in Available Service may be assigned that turn (see Step 1 Rotate Service). (page 8)

Yes, but only as specified: the Housekeeper always may stand in for a lady's maid; the Underbutler may act as any male servant only if you acquired the Butler’s Pantry service tile and took the underbutler; and footmen may substitute for valets only after you buy the Brushing Room service tile (which grants that ability to all your footmen). (page 9)

You take favours during the Enjoy Favours step after providing service, in this order: collect pounds, then add reputation, then invite/dismiss guests; all favours are mandatory except the dismiss-guest option, which is explicitly optional. (pages 9–10, 16)

Purchased tiles are placed face‑up in the proper column of your Country Estate Organiser; you may not buy a duplicate improvement tile you already own, but duplicate copies can be stacked in the market for other players to buy; after purchase slide market tiles left and draw from the tile bag to refill the rightmost space and never leave an open market space if tiles remain. (pages 10–11)

When you Pass you still apply Step 2 effects, then refresh service (all servants go to Available Service) and take your Discard Pile back into your Active Hand; you then choose either to collect £200 rent or refresh the Builders' Market for free, and afterward you may optionally purchase from the market. (page 13)