Like most Magic: The Gathering cards, the value of Alberix, the Trade Planet depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Mystery Booster 2)
You either reveal a Land, which you get to put into your hand, or you reveal a non-Land card, which you can either leave on top of your library or put into your graveyard
Irma copies exactly what was printed on the original creature and nothing else, with the listed exceptions (unless that creature is copying something else
Once we were removing cards from the game, it became clear that we could hit more areas other than just the library
He was turned immortal by Yawgmoth so Crovax and Ertai could torture him forever, but it ended up being an advantage for Squee whos still alive in Dominaria