Amritsar: Le Temple d'Or

They are separate: your turn has Phase 1 (optional) to move your Elephant, Phase 2 (obligatory) to move Workers, and a possible Phase 3 Elephant move only if you unlocked the Movement Token on your board (see p.5–6).

Yes — immediately after the active player finishes, other players clockwise may ‘follow’ and perform the Mahout action matching that Worker colour if they have it on their board; the active player scores 1 PP per follower (p.7).

You can only make donations using a Mahout Tile and only in the District where your Elephant is located; Donation Tiles have 4 Levels with specific resource costs and higher-Level spaces require the two spaces below to be occupied, and you gain PP as described when placing a Counter (p.5).

No — on the same turn you cannot buy and sell the same type of Resource, even if you perform multiple Market actions; also any Market action where you buy or sell grants a Donation Counter from your Market space to your Elephant (p.9).

Acquired Storehouses can grant an immediate benefit (taken when you add that Storehouse) and/or a permanent benefit that applies for the rest of the game; your Starting Storehouse has no benefit (p.12).

You get the Benefit shown for the step immediately when you move up a Knowledge track; additionally the rules list special End-of-Decade and End-of-Game Knowledge effects that apply at those times (p.11).