In the case of the former, its because the best choices vary not only by color identity, but often by specific deck building limitations: Seismic Assault and many other red effects want you to play an extra-high land count, while a black deck with reanimation and Tortured Existence obviously cares about discarding creatures
All players have Timmy moments
The last main tab is for a Public Gallery, which displays creations by other users
Printed only once way back in 2008 as part of the Morningtide set from Lorwyn block, Sensation Gorger is a card that some goblin players may not even know about
A Basic Water-type Pokmon with 140 HP, it shares the powerful Legendary Pulse ability, letting the player draw a card at the end of every turn
Its always beneficial to have choices, and Deeproot Elite gives you much more control than Metallic Mimic does