There are several suggestions from the other threads that could be added here for testing.

  1. Connection quality evaluation and determining limits types of games (1v1, 2v2, etc) based on connection quality.
  2. Testing drops and their impact on the remaining players in the game and any ladders/rankings afterwards.
  3. Pre-/in-/post-game communications - chat foyer, voice, messaging.
  4. Matchmaking flexibility for random opponents, private clan/group games, and tournaments.
  5. Grouping options, formations, commands
  6. Balance of units vs each other in cost, combat and movement in MP environment.
  7. Terrain and weather effects to visibility, movement, combat, missile fire. Thinking of things like fog of war, guns in rain, fatigue in snow, hills blocking missile fire and so on.
  8. Morale effects of guns, being flanked, proximity of taisho, other routing units friend/foe, charges, etc.
I'm sure the Ten Thousand Game club members can greatly expand the details of these and add a ton more.