ANCUR UFAQ 24 [Michael Boggs]

If the Runner takes Meridian as a -1 point agenda, does the Corp still gain 4?

No.

If Meridian is hosting a Sub Boost when the Runner chooses to add Meridian to their score area, does the run still end?

No. Once Meridian is uninstalled, all hosted cards and counters are trashed, the encounter ends, and the Runner passes the position Meridian had occupied.

What happens if the Corp uses Wormhole to resolve Meridian's subroutine?

The subroutine resolves as normal. The Runner can add Meridian to their score area; if they don't the run ends and the Corp gains 4.

What happens if the Corp uses Loki to copy Meridian's subroutine?

Loki gains the text of the subroutine exactly as it appears on Meridian. The self-reference to Meridian is thus broken. Since the Runner cannot add either Meridian or Loki to their score area, the subroutine is forced to end the run and gain the Corp 4.