Collective Restraint

• WWizards of the Coast2007-02-01
  Official Ruling
  In the Two-Headed Giant format, you still only have to pay once per creature.
• WWizards of the Coast2014-02-01
  Official Ruling
  Unless some effect explicitly says otherwise, a creature that can't attack you can still attack a planeswalker you control.
• WWizards of the Coast2021-06-18
  Official Ruling
  The basic land types are Plains, Island, Swamp, Mountain, and Forest. Land types other than basic land types (such as Desert) don't contribute to domain abilities.
• WWizards of the Coast2021-06-18
  Official Ruling
  Domain abilities count the number of basic land types among lands you control, not how many lands you control or how many of any type.

Rulings via Scryfall