If it's small enough, it kills it, but if it's bigger, it weakens it for the turn, making it more vulnerable
Some holographic cards are already proving to be valuable so scalpers have been buying up these McDonalds Pokemon cards so you will need to check availability in your location
There are also a fair few new Brothers War cards that nearly ended up on the list including the new Urza, Planeswalker
Probably not--prices always taper off once a new set is released
Random discard is never a good idea unless you like to Gamble, but at least here the possibility to gain value from it is a little higher, so dig out your Tibalts that have been gathering dust in that binder of yours and sleeve em up
Though you might make an enemy with this cat, you're just as likely to make an ally