If a landmark minion with a spire reward is not on a Source well, can I construct a spire for free when I defeat it?

Are Gateport landmarks considered path hexes for the purposes of connection to possible marks?

Can spires attack landmark minions?

Do I get to level up with a hero that removes the last health off the Altar of Aggression?

Does teleporting using a Gateport landmark's Riftwalk talent cost any movement?

How much Source do I gain when I reveal the Naroran Altar landmark?