If I use Gengar's "Cursed Drop" attack, can I put damage counters on more than one of my opponent's Pokemon, or do I have to put all four counters on one Pokemon?
You can put the 4 damage counters on their Pokemon in any way that you like.
Source:
Triumphant FAQ (2010-11-04), PUI Rules Team (2010-11-04)
When using Rotom's "Plasma Arrow" attack, I get to choose one of the opponent's Pokemon and do 20 damage for each Energy attached to it; but do I do the damage to the Defending Pokemon, or to the Pokemon I chose?
To the Pokemon that was chosen. If the damage were to be done to the Defending Pokemon, there would be a "20x" value in the damage field of the attack.
Source:
Undaunted FAQ (2010-09-09), PUI Rules Team (2010-09-09)
What happens if one of the players doesn't have a benched Pokemon when using Drifblim's "Take Away" attack?
There is no restriction on using the attack if there is no benched Pokemon. If a player has no Benched Pokemon, that player loses. If neither player has Benched Pokemon, then it is a tie and a game of Sudden Death must be played.
Source:
Undaunted FAQ (2010-09-09), PUI Rules Team (2010-09-09)
Can Espeon's "Solar Suggestion" attack place damage counters onto a Jolteon that can't be hit by effects due to a successful coin flip during its "Agility" attack, or onto a Toxicroak [G] with its "Anticipation" Poke-BODY enabled? If I can't place them, what do I do with the damage counters I removed from my Pokemon?
You cannot place damage counters onto that Jolteon or Toxicroak [G], but you can still remove damage counters from your own Pokemon. If you select a Pokemon under the status of not receiving effects, the damage counters that would be placed onto that Pokemon simply disappear from play.
Source:
Undaunted FAQ (2010-09-09), PUI Rules Team (2010-09-09)
A Vespiquen that used its "Mach Wind" attack on my previous turn was hit by Grimer's "Sticky Liquid" attack during my opponent's turn. In this instance, what is Vespiquen's retreat cost during my next turn?
It has no Retreat Cost. When effects that increase something like Retreat Cost by a particular amount are stacked on top of effects that make something like Retreat Cost vanish, the vanishing effect takes priority.
Source:
Undaunted FAQ (2010-09-09), PUI Rules Team (2010-09-09)
If I choose 4 damage counters on my Pokemon with Espeon's "Solar Suggestion" attack, can I then place 3 or fewer damage counters on my opponent's Pokemon?
No, you can't. You must place the same number of damage counters on your opponent's Pokemon as you removed from your own Pokemon.
Source:
Undaunted FAQ (2010-09-09), PUI Rules Team (2010-09-09)