Reign of Cthulhu

Walk moves you along connecting lines to an adjacent location; Take the Bus is done from a bus station by discarding Clue cards as specified to move within or between towns; Use a Gate moves you from one gate location to another (you cannot move to/from sealed gates) and any gate movement requires a Sanity roll after completing it (p.6).

Yes — you must be at the location: Defeat a Cultist is a 1-action to remove one cultist, Defeat a Shoggoth costs 3 actions (all on the same turn) and grants a Relic when defeated, and Seal a Gate is a special action where you discard five matching Clue cards to place the Seal token and remove one cultist from each location in that town (pp.6–7).

When you draw an Evil Stirs, resolve it immediately by (1) rolling the Sanity die, (2) revealing the next Old One, (3) placing a Shoggoth using the bottom Summoning card, and (4) reshuffling the Summoning discard pile onto the top of the Summoning deck; Evil Stirs cards are removed from the game after resolution, and if you draw two you resolve these steps twice (p.7).

In the Summoning step flip as many Summoning cards as the current summoning rate and place a cultist on each named location; if a location already has three cultists (or a Shoggoth cannot be placed), an awakening ritual occurs and you reveal the next Old One (p.8).

You roll the Sanity die after using a gate, after resolving a Relic, when entering (or a Shoggoth enters) a location with a Shoggoth, and as the first step of an Evil Stirs card; die results cause sanity loss or add cultists, and if you lose all sanity you flip to your insane side (fewer actions and a changed ability) — sealing a gate or certain effects can return you to sane as described in the rules (p.9, p.12).

You win immediately when all four gates are sealed; you lose if the last Old One (Cthulhu) awakens, there are not enough cultists or Shoggoths to place when required, you cannot draw two Player cards when instructed, or all players are insane (pp.3, 9).