Trainers » *Trainers in General
When you use a Trainer card, first you pay the cost (if any), then you resolve the effect of the Trainer card, then you discard that Trainer card. So you could NOT use Item Finder to bring itself back from the discard pile (you would discard 2 other cards from your hand, then pull a Trainer card from your discard pile to your hand, THEN you would discard the Item Finder).
Source: WotC Chat (2000-03-02)
Trainers » Switch
Can the Switch card be used to retreat a Paralyzed, Confused, or Sleeping Pokémon?
Yes, you can use a Switch card to retreat a Confused, Asleep or Paralyzed Pokémon.
Source: WotC Chat (2000-02-03)