Lost Ruins of Arnak: Twisted Paths

No. Replace it with the Twisted Paths board, choosing either the Spider Temple or Owl Temple side. The new research tracks are designed for leaders from Expedition Leaders or The Missing Expedition, though you can play without them (p. 3).

As a main action, you need a dark tablet and a research token positioned on or above the altar. Put one dark tablet below it; if it’s empty, take an artifact from the card row and place it there, or resolve the artifact already there. You may have at most three of your tablets at each altar (p. 4).

Unused dark tablets go back to the supply at game end. Each tablet placed on an altar then costs points according to the rightmost empty space in the supply; after that, the player with the most tablets at each altar scores its printed points, with tied players each scoring them (p. 5).

Not if the card merely activates the site. You get the dark effect after digging at, relocating to, or discovering one of the four marked sites with an archaeologist; an effect that places or relocates an archaeologist can qualify (p. 5).

No. Each passage can be explored only once, and after you take one, your magnifying glass stays there for the rest of the game. On later Research actions, move your lantern or notebook instead; the notebook can advance only up to the higher of your magnifying glass or lantern (p. 6).

Once you reach row 5, you can buy a 1-point tile or an idol; at row 7, you can also buy a 5-point tile; and at row 9, you can buy any temple tile. Tiles along the research track can be bought when one of your research tokens is on their space, using a Research action and paying the shown cost (p. 7).