Why is there no Word Games Forum or Subdomain?
There should be a Word Games Subdomain, or at least a Word Games Forum!
Can the Wild Will Flare be used to have an encounter EVEN when a Wild Destiny Card that specifies any target is drawn?
No. It specifically says, "when you draw a player's color..."
Also, does a Wild Destiny Card allow a player to attack themselves? (So they could reestablish a home colony or root out enemy colonizers for example)?
No. It specifically says, "with any other player...in his or her home system".
Read the cards.
In previous editions of the game, Wild Destiny cards could be used to encounter home planets, and if you want to house rule that you can for this edition, you can. It might make the games a bit longer, though.
Note also that Special Destiny cards also only allow encounters in other systems.