Mombasa

After you use a card for an action you must flip it face down; flipped cards cannot be used any more (page 5).

At the end of your own action phase you pick up exactly one resting deck into your hand; during cleanup you then move each card from its action slot up to its linked resting deck, and only one resting deck is recovered per turn (pages 4 and 9).

Yes — the total unit value of the goods cards you use can be spent to acquire at most one card from the display and/or to advance on one or more company tracks, and any remaining units after buying a card can be divided among tracks as you wish (page 5).

No — you take trading posts from the company base and place them on their side to mark entry while spending expansion points; once you have used your expansion value you collect the rewards, oust/return any other trading posts, then tip the new trading posts upright (page 6).

No — majority bonus spaces explicitly do not use up the cards in your action area, so you do not flip them when taking that bonus (page 8).

Whenever your track marker would cross a capital call you must immediately pay the shown pounds to the bank or your marker must remain on the space before the capital call; if a reward would move you but you cannot pay or reach the end, move as far as possible and forfeit the rest, and reaching/passing special spaces also grants payouts and unlocks bonuses (page 11).